MEMCAL    SCHOOL 
UISMAmif 


Digitized  by  the  Internet  Archive 

in  2007  with  funding  from 

IVIicrosoft  Corporation 


http://www.archive.org/details/bacteriologymanuOOzapfrich 


PLATE   1. 


FIG.   1. 


^|HIf 


V. 


Cover-glass  preparation  of  pericardial  exudate,  showing 
bacillus  pyoeyaneus  stained  blue,  and  the  bacillus  tuber- 
culosis stained  red.    (Ernst.) 


FIG.  2. 


'    *»         'J 


Urethral  discharge  from  a  case  of  gonorrhoea,  showing 
gonococci  enclosed  in  pus  corpuscles,  and  lying  free  in  the 
discharge.      Stained    with  methylene  blue.     (C.   E.  Simon.) 


bca's  Scries  of  Pocket  Tcxt«5ool<s. 

BACTERIOLOGY. 

A  MANUAL  FOR  STUDENTS  AND  PRACTITIONERS. 


-BY 


FRED.  C.  ZAPF:^E,  M.D., 


Profess&r  of  Pathology  and  Bacteriology  in  the  Illihois  Medical  College;  Professor 

of  Histology  in  the  Department  of  Medicine  and  in  the  School  of 

Dentistry  of  the  University  of  lUinois,  Chicago. 


SERIES  EpiTED  BY 
B.   GALLAUDET,   M.D., 

Demonstrator  of  Anatomy  and  Instructor  in  Surgery,  College  of  Physicians  and  Surgeons, 
Columbia  University,  New  Yei-k ;   Visiting  Surgeon,  Bellevue  Hospital,  New  Yoik. 


ILLUSTRATED   WITH   ONE   HUNDRED   AND   FORTY-SIX 
ENGRAVINGS  AND  SEVEN    COLORED  PLATES. 


LEA   BROTHERS  &  CO., 
PHILADELPHIA    AND    NEW    YORK. 


Entered  according  to  Act  of  Congress,  in  the  year  1903,  by 

LEA  BROTHERS  &  CO., 

In  the  Office  of  the  Librarian  of  Congress.    All  rights  reserved. 


ELEOTROTYPED  BY  PRESS    OF 

WESTCOTT  <t  THOMSON,   PHILADA,  \VM.  J.   DORNAN,   PHILAOA. 


I  (7,-/-:-. 


PREFACE 


In  preparing  this  volume  it  has  been  the  author's  aim  to 
furnish  the  student  and  general  practitioner  with  a  book  on 
Bacteriology  from  which  all  unnecessary  scientific  discussions 
have  been  excluded. 

All  the  matter  has  been  carefully  gone  over ;  and  in  its 
finished  form  this  book  presents  Bacteriology  from  a  stand- 
point which  enables  the  beginner  to  gain  a  full  and  compre- 
hensive view  not  only  of  this  subject  itself,  but  also  of  its 
practical  relation  to  medicine. 

The  book  is  systematically  arranged  on  the  basis  of  the 
course  of  lectures  and  laboratory  exercises  given  by  the 
writer  for  several  years  past ;  and  is  also  a  composite  of 
what  to  his  mind  are  the  most  valuable  features  of  the  larger 
works,  the  practical  side  of  Bacteriology  being  especially 
emphasized. 

Each  chapter  is  intended  to  represent  one  lecture,  although 
in  some  instances  two  chapters  are  embraced  because  of  the 
brevity  of  the  subjects  contained. 

The  limited  scope  of  this  work  has  made  it  impossible  to 
give  credit  in  the  text  to  the  references  used  ;  but  the  author 
wishes  to  acknowledge  his  obligations  to  the  works  o'f 
Abbott,  Park,  McFarland,  Sternberg,  Levy  and  Klemperer, 
Vaughan  and  Novy,  and  Newman,  of  which  free  use  has 
been  made  in  the  preparation  of  the  text. 

F.  C.  Z. 

224  Central  Park  Av., 
Chicago,  1903. 


o24 


CONTENTS. 


PART  I. 

CHAPTER  I. 

PAGES 

Morphology  of  Bacteria 17-27 

CHAPTER  II. 
Biology  of  Bacteria 28-35 

CHAPTER  HI. 

Cultivation  of  Bacteria. — Preparation  of  Media 36-44 

CHAPTER  IV. 

Sterilization  and  Disinfection. — Sterilization  of  Culture- 
media  AND  Laboratory  Apparatus. — Disinfection  of 
Instruments,  Surgical  Material,  etc 45-55 

CHAPTER  V. 
Antiseptics  and  Disinfectants 56-60 

CHAPTER  VI. 
Practical  Directions  for  Disinfection 61-64 

CHAPTER  VII. 

Cultures  and  their  Study.— How  to  make  Cultures    .    .    .    65-75 

CHAPTER  VIII. 
Cultivation  of  Anaerobic  Bacteria  . 76-79 

CHAPTER  IX. 
Microscopic  Examination  of  Bacteria 80-92 

CHAPTER  X. 

Experiments  on  Animals 93-97 

5 


6  CONTENTS, 

CHAPTER  XL 

PAGES 

Poisonous  Products  of  Bacteria 98-100 

CHAPTER  Xn. 
Infection 101-112 

CHAPTER  XIII. 
Immunity 113-123 

CHAPTER  XIV. 

Antitoxin. — Source,  Nature,  and  Action. — Artificial  Pro- 
duction AND  Method  of  Administration      ......    124-129 

CHAPTER  XV. 
Examination  of  Air,  Soil,  and  Water 130-139 


PART  II. 

CHAPTER  I. 

Non-pathogenic  Bacteria. — Schizomycetes 141-148 

CHAPTER  II. 
Moulds  or  Filamentous  Fungi. — Hyphomycetes 149-155 

CHAPTER  III. 
Yeasts  or  Budding  Fungi.— Saccharomycetes 156-158 


PART  III. 
PATHOGENIC  BACTERIA. 

CHAPTER  I. 
Suppuration. — Staphylococci  ;  Streptococci  ;  Bacillus  Pyo- 

CYANEUs:  Micrococcus  Tetragenus 159-172 


CONTENTS.  7 

CHAPTER  II. 

PAGES 

Suppuration  {Continued). — Micrococcus  GtONORrhce^;  Dip- 
Lococcus  Intracellulars  Meningitidis;  Diplococcus 
Lanceolatus;  Bacillus  of  Friedlaender 173-186 

CHAPTER  III. 
Bacillus  Tuberculosis 187-198 

CHAPTER  IV. 

Bacillus  Tuberculosis  (Cbn^mued).— Bovine  Tuberculosis, 
Fowl  Tuberculosis;  Pseudotuberculosis;  Bacillus 
Smegmatis 199-208 

CHAPTER  V. 

Organisms  resembling   Bacillus    Tuberculosis;   Bacillus 

OF  Leprosy;  Bacillus  of  Syphilis 209-216 

CHAPTER  VI. 
Bacillus  OF  Glanders  ;  Actinomycosis  ;  Rhinoscleroma  .   .    217-227 

CHAPTER  VII. 
Bacillus  of  Tetanus  ;  Pseudotetanus .    228-235 

CHAPTER  VIII. 
Bacillus  of  Diphtheria;  Pseudodiphtheria 236-249 

CHAPTER  IX. 

Spirillum   of   Cholera;    Cholera    Nostras   and   Summer 

DiARRHCEA 250-259 

CHAPTER  X. 
Organisms  resembling  the  Cholera  Spirillum  ;  Spirillum 
OF  Finkler-Prior  ;  Spirillum  Deneke  ;  Spirillum  Mp:t- 
scHNiKOVi,  etc 260-267 

CHAPTER  XI. 
Bacillus  Typhosus 268-282 

CHAPTER  XII. 
Organisms  resembling  Bacillus  Typhosus;  Bacillus  Coli 
Communis;     Bacillus    Enteritidis;     Bacillus    Dysen- 
teric ;  Bacillus  Paratyphosus 283-288 


8  CONTENTS. 

CHAPTER  XIII. 

PAGES 

Bacillus   Icteroides;    Bacillus    Pestis;    Bacillus   Influ- 
enza      289-298 

CHAPTER  XIV. 

Bacillus  Anthracis  ;  Bacillus  Anthracoides;  Bacillus  of 

Symptomatic  Anthrax;  Hydrophobia 299-310 

CHAPTER  XV. 

Bacillus  of  Malignant  (Edema  ;  Bacillus  Aerogenes  Cap- 

suLATis;   Bacillus  Proteus  Vulgaris 311-314 

CHAPTER  XVI. 
Malta  Fever;  Mumps;  Relapsing  Fever ;  Whooping-cough    315-319 

CHAPTER  XVII. 

Acute  Exanthemata;   Measles;   Scarlet   Fever;   Small- 
pox         320-325 


PAKT  IV. 

ORGANISMS  PATHOGENIC  FOR  ANIMALS  ONLY. 

Chicken  Cholera;  Hog  Cholera;  Swine  Plague;  Typhus 

Murium;  Mouse  Septicemia 327-330 


appendix. 

Student's  Individual  Bacteriology  Outfit     331 

Syllabus  for  Laboratory  Work 332-335 

Index 337 


BACTERIOLOGY 


PART  I 


CHAPTER  I. 

MORPHOLOGY  OF   BACTERIA. 

Description:  Bacteria  are  minute  unicellular  vegetable 
organisms  which  resemble  an  ordinary  tissue-cell.  They 
belong  to  the  fission-fungi,  a  subdivision  of  the  Thallophytcey  a 
class  of  the  Oryptogamia.  They  differ  from  lichens  ^nd  algae 
in  that  they  contain  no  chlorophyll  and  live  only  on  organic 
matter. 

The  fission-fungi  are  divided  into  : 
ScHizoMYCETES — bacteria. 

H  YPHOM  YCETES — m  oulds. 

Saccharomycetes — yeasts. 

All  bacteria  possess  a  limiting  cell-wall  or  capsule,  which 
encloses  a  homogeneous  or  granular  cell-protoplasm  and  a 
nucleus. 

This  protoplasm  consists  principally  of  an  albuminous  sub- 
stance known  as  inycoprotein.  The  chemical  formula  of  this 
proteid  substance  is  C25H42N6O0. 

Water  and  salts  also  enter  largely  into  the  chemical  com- 
position of  bacteria.  One  group,  the  Beggiatoa,  a  higher 
species  of  plant,  contains  in  addition  sulphur  granules.  When 
grown  on  culture-media,  the  composition  of  bacteria  is  subject 
to  variations  depending  upon  the  kind  of  media  used. 

The  anilin  dyes,  which  are  used  almost  exclusively  for 
staining  bacteria,  stain  the  organism  uniformly  so  that  the 
nucleus  is  obscured ;  but  when  special  nuclear  stains  are  used, 
2— Bact.  17 


18  MORPHOLOGY  OF  BACTERIA. 

it  is  possible  to  distinguish  the  nucleus  with  a  high-power 
lens  (y2  ^^^  immersion).  The  extreme  minuteness  of  bacteria 
is  more  or  less  of  an  obstacle  to  making  studies  of  their  real 
appearance. 

Some  bacteria  [Bacillus  Megaterimii)  contain  also  very 
deeply  staining  granules.  These  granules  are  of  two  kinds : 
metachromatlG  granules,  which  are  believed  to  be  the  result 
of  a  degenerative  process ;  and  polar  granules,  which  are  still 
a  matter  of  speculation.  It  was  discovered  recently  that  the 
protoplasm  of  many  bacteria  also  contains  fat  droplets.  This 
finding  may  possibly  be  of  service  in  diiFerentiating  certain 
organisms. 

Cell-membrane:  The  cell-membrane  is  usually  quite  thin, 
but  it  may  be  of  such  thickness  as  to  resemble  a  distinct  cap- 
sule or  envelope  of  mucus.  Such  a  capsule  is  seen  to  best  ad- 
vantage enclosing  tlie  pneumococcus  when  the  germ  is  exam- 
ined in  the  sputum  of  an  individual  suffering  from  lobar 
pneumonia.  The  capsule  is  seen  rarely  when  the  organism  is 
grown  artificially.  This  is  true  of  all  pathogenic  bacteria. 
Special  reagents  and  stains  must  be  used  for  the  demonstra- 
tion of  this  capsule.  The  methods  will  be  described  later,  in 
the  chapter  on  Microscopic  Examination  of  Bacteria. 

Flagella  and  Motility  :  Many  varieties  of  bacteria  have 
very  delicate  projections  of  the  cell-membrane,  called  flagella, 
which  appear  to  be  organs  of  locomotion.  So  far  as  their 
appearance  is  concerned,  they  correspond  to  the  cilia  of  an 
epithelial  cell.  Some  bacteria  have  only  one  or  more  terminal 
flagella  (Fig.  1),  while  others  have  both  terminal  and  lateral 
flagella.  The  number  varies  from  one  terminal  flagellum — 
monotrichia  ( Vibrio  cJiolerm),  to  two  or  more  at  each  end — 
rophotrichia  (Bacterium  syncyaneum).  Organisms  with  both 
tefmmal  and  lateral  flagella  belong  to  the  class  peritrickia, 
(Bacillus  typhosus).  These  flagella,  with  one  exception 
(Micrococcus  agilis  of  Ali-Cohn),  are  seen  only  on  the  rod- 
shaped  or  spiral  bacteria.  The  most  active  bacteria  usually 
have  the  greatest  number  of  flagella,  although  there  are  a  few 
bacteria  which  are  well  supplied  with  flagella  and  yet  are 
devoid  of  motility  ;  and  others  with  few  flagella  are  actively 
motile.     It  has  been  suggested  that  the  flagella,  in  addition 


SIZE, 


19 


to  being  organs  of  locomotion,  aid  to  increase  the  food-supply 
of  tlie  germ  by  stimulating  the  flow  of  the  current  of  the 
nutrient  fluids  past  the  bacterium. 

The  so-called  Brownian  movement  is  observed  frequently  in 
bacteria,  and  especially  In  the  cocci.  It  is  simply  a  molecular 
movement  or  rearrangement  of  the  protoplasmic  granules 
without  changing  the  position  of  the  organism  in  the  least. 
The  spirilla  frequently  exhibit  a  rotary  movement j  which  may 
be  very  rapid.     The  movement  due  to  the  currents  present  in 


?t^ 


Fig.  1. 


a.  Spiral  forms  with  a  flagellum  at  only  one  end.  6.  Bacillus  of  typhoid  fever 
with  flagella  given  off  from  all  sides,  c.  Large  spirals  from  stagnant  water  with 
wisps  of  flagella  at  their  ends  (Spirillum  undula).    (Abbott.) 

all  fluids  must  not  be  confused  with  actual  motility.  Fre- 
quently it  is  mistaken  for  such,  especially  when  the  organism 
is  examined  in  the  hanging  drop. 

Size :  Bacteria  vary  greatly  in  size.  The  micromillimeter 
is  the  standard  of  bacteriologic  measurement.  It  is  equal  to 
about  -^z^w^  ^^  ^^  inch.  The  cocci  are  the  smallest  bacteria, 
and  the  twisted,  spiral,  or  chain  organisms  the  largest.  The 
cocci  vary  in  size  from  0.1 //  to  2.8//;  the  bacilli  range  from 
1  /i  X  0.2  /i  to  5  //  X  1 .5  [1.  The  anthrax  bacillus  is  the  largest 
of  the  bacillus  group,  and  the  bacillus  of  mouse  septicaemia 
the  smallest.  Some  of  the  spirilla  are  as  many  as  40  fi  in 
length  (spirillum  of  relapsing  fever).  It  is  almost  impossible 
to  form  any  definite  conception  of  the  size  of  bacteria.  In 
order  to  determine  their  measurements  special  microscopic 
attachments  are  necessary.  The  freight  can  be  arrived  at  by 
a  lengthy  mathematical  calculation.  Naegeli  estimated  tlie 
weight  of  an  average  organism  at  iooOQOQOTr'g'7  ^^  ^  milligram. 


20  MORPHOLOGY  OF  BACTERIA, 

This  is  by  no  means  a  visionary  calculation,  but  the  actual 
weight. 

Reproduction  :  Bacteria  multiply  in  two  ways,  hy  fission 
or  binary  division^  and  by  sporulation. 

When  all  the  conditions  necessary  for  growth  are  present, 
fission  progresses  with  astonishing  rapidity.  When  the  bac- 
terium is  ready  to  divide,  it  is  seen  first  to  increase  slightly 
in  size,  and  then  it  is  divided  into  two  nearly  equal  parts  by 
a  gradual  constriction  in  the  middle.  If  the  separation  is 
incomplete,  chains  of  varying  length  are  formed.  The 
rapidity  with  which  this  phenomenon  occurs  is  entirely  de- 
pendent upon  conditions  influencing  the  growth  of  the  organ- 
ism. If  these  conditions  are  favorable,  millions  of  bacteria 
will  develop  from  a  single  organism  in  the  course  of  twenty- 
four  hours.  It  has  been  estimated  that  if  each  organism 
reproduces  itself  by  binary  division  once  every  hour,  the 
result  in  twenty-four  hours  will  be  16,777,200  individual 
germs,  or  281,500,000,000  in  forty-eight  hours. 

Reproduction  by  sporulation  resembles  the  seeding  process 
of  the  higher  plants.  It  is  seen  mostly  in  the  rod-shaped 
bacteria,  especially  when  they  are  no  longer  purely  vegetative 
or  when  conditions  for  rapid  multiplication  are  unfavorable. 
Fraenkel  says  that  sporulation  is  an  indication  of  the  vital 
perfection  of  an  organism,  and  not  a  sign  of  deficient  nutri- 
tion. These  spores  are  oval  or  spherical,  very  refractive 
little  bodies  which  develop  within  the  organism  itself,  and 
are  termed  endospores.  They  usually  develop  singly,  and 
are  situated  either  at  the  end  or  in  the  centre  of  the  germ 
(Figs.  2,  3,  4).  When  they  are  of  unusually  large  size  the 
shape  of  the  parent  cell  is  changed  correspondingly.  Thus 
spindles,  Clostridia,  and  drum-sticks  may  result.  The  spore 
is  set  free  by  a  degeneration  of  the  parent  germ.  Spores  do 
not  stain  well  with  the  ordinary  methods  of  staining,  and 
they  are  also  very  resistant  to  drying,  heat,  light,  and  chem- 
icals. These  properties  are  due  to  a  very  thick  and  almost 
impenetrable  membrane  by  which  they  are  enclosed.  This 
peculiar  resistance  to  extraneous  influences  is  of  great  impor- 
tance in  surgery  and  also  in  the  cultivation  of  bacteria.  It 
will  be  considered  more  fully  later. 


REPRODUCTION. 


21 


Reproduction  by  arthrospores  is  recognized  by  many  prom- 
inent bacteriologists.  It  is  seen  especially  in  the  coccus  group. 
Various  definitions  of  this  method  of  reproduction  have  been 
given.     According  to  Hueppe  (and  he  is  probably  correct), 


Fig.  2. 


Unstained  spores  in  slightly  distended  bacilli.    (The  spores  are  the  light  spots  in 
heavily  stained  bacilli.)    (Park.) 


Fig.  3. 


Fig.  4. 


Spores  in  distended  ends  of 
bacilli.    (Park.) 


Unstained  spores  in  centre  of  bacilli 
arranged  in  chains.    (Park.) 


they  are  larger  and  more  resistant  cells  which  take  charge  of 
the  perpetuation  of  the  species  in  the  guise  of  a  resting-stage 
or  spore.  Apparently  the  spore  is  evolved  from  the  entire 
germ,  or  represents  a  transformation  of  the  germ  into  a  spore. 


22  MORPHOLOGY  OF  BACTERIA. 

Another  equally  plausible  explanation  is  that  it  is  a  sprout 
from  one  end  of  the  cell,  or  a  constriction  ;  but  this  definition 
is  not  so  satisfactory  as  that  of  Hueppe. 

Whenever  spore-formation  is  referred  to,  the  endogenous 
spore  (endospore)  is  meant  unless  the  other  variety  is  men- 
tioned specifically. 

Ci^ASSiFiCATioN :  It  is  rather  difficult  to  classify  bacteria 
properly.  In  order  to  include  all  the  varieties  and  species, 
several  classifications  must  be  made. 

First,  as  to  their  shape,  we  have  three  principal  divisions 
or  groups  :  micrococci,  bacilli,  and  spirilla. 

The  micrococci  (Fig.  5)  are  spherical  or  slightly  oval  in 


Fig.  5. 


a  h 


00    oo  - 


•^  J  ^  ®B8 


90 


d 


a.  staphylococci,    b.  Streptococci,    c.  Dlplococci.    d.  Tetrads,   e.  Sarcinse, 
(Abbott.) 

shape,  non-motile,  and  do  not  form  spores.  They  grow  by 
binary  division.  This  group  is  subdivided  further  into  the 
following  varieties : 

Diplococcus:  two  micrococci  remaining  attached  to  each 
other,  or  an  imperfect  division.  They  may  be  absolutely 
spherical  or  the  contiguous  surfaces  may  be  slightly  flattened 
or  concave,  the  "biscuit"  coccus  or  "  semmelkokken." 

Tetrad :  a  group  of  four  cocci,  the  result  of  division  in  two 
directions. 

Sarcina :  a  packet  or  cube  of  eiglit  cocci,  the  result  of  divi- 


CLASSIFICATION.  23 

sion  in  three  directions.  This  form  resembles  in  appearance 
a  bale  of  cotton  or  a  dice. 

Staphylococcus :  the  most  common  form,  in  which  the  cocci 
occur  in  irregular  groups  of  varying  numbers  and  without 
definite  arrangement.  The  name  is  derived  from  the  Greek 
aiaifulrj^  and  is  given  to  this  form  because  of  resemblance  to 
a  bunch  of  grapes. 

Streptococcus:  chains  of  cocci.  When  division  occurs  in 
only  one  direction,  with  adhesion  or  attachment  of  the  indi- 
vidual members,  chains  of  varying  length  are  formed.  Some 
authors  distinguish  a  streptococcus  longus  and  a  streptococcus 
brevis, — that  is,  long  chain  and  short  chain ;  and   a  few,  a 

Fig.  6. 


.*-> — 


a.  Bacilli  in  pairs.    5.  Single  bacilli,    c  and  d.  Bacilli  in  threads. 
e  and  /.  Bacilli  of  variable  morphology.    (Abbott.) 

streptococcus  conglomeratus.  When  the  chain  is  composed 
of  diplococci,  it  is  called  a  streptodiplococcus. 

Ascococcns  and  leuconostoc  are  two  very  unusual  groupings 
of  cocci.  In  the  former  the  cocci  are  associated  in  globular 
or  lobulated  masses  held  together  by  a  firm,  gelatinous,  intra- 
cellular substance.  In  the  second  variety  the  cocci  grow  in 
chains  or  masses,  and  are  surrounded  or  enclosed  by  a  very 
thick  and  tough  gelatinous  capsule. 

The  bacilli  (Fig.  6)  are  rod-shaped  or  filamentous  bacteria, 
motile  or  non-motile,  flagellated  or  not,  reproducing  them- 
selves both  by  fission  and  sporulatlon.  They  are  not  sub- 
divided into  groups,  but  exhibit  considerable  variation  of 


24  MORPHOLOGY  OF  BACTERIA, 

shape.  Some  are  quite  short  and  thick ;  others  long  and 
slender;  some  very  large  and  some  very  small.  They  may 
be  so  short  as  to  resemble  a  coccus,  hence  the  term  oval 
coccus.  Some  have  rounded  ends ;  others  pointed,  squared, 
or  slightly  concave  ends.  They  may  be  spindle-shaped,  rod- 
shaped,  club-shaped,  or  a  Clostridium  shape.  Their  arrange- 
ment is  in  some  instances  characteristic.  They  may  be  seen 
to  lie  singly  or  in  pairs,  in  parallel  rows  or  in  chains  of  vary- 
ing length,  sometimes  interlacing  freely.  Very  long,  slender, 
and  indistinctly  articulated  filamentous  bacilli  are  known  as 
leptothnx;  when  these  filaments  present  pseudobranchings, 
they  are  termed  cladothrix. 

The  spirilla  (Fig.  7)  are  curved  or  twisted  rods  of  varying 
length,  endowed  with  motility  and  a  peculiar  rotary  move- 
ment, flagellated  and  reproducing  themselves  by  both  fission 

Fig.  7. 


a  6  c  d 

a  and  d.  Spirilla  in  short  segments  and  longer  threads— the  so-called  comma 
forms  and  spirals,  b.  The  forms  known  as  spirochseta.  c.  The  thick  spirals  some- 
times known  as  vibrios.    (Abbott.) 

and  sporulation.  They  may  be  very  rigid  or  exceedingly 
flexible.  The  short,  slightly  bent  rods  resemble  a  comma  so 
closely  that  they  frequently  are  referred  to  as  "  comma  "  bacilli 
(cholera),  or  as  a  vibrio  because  of  their  vibratory  motion. 
The  extremely  long  and  flexible  forms  are  called  spirochceta 
(relapsing  fever).  A  spiromonas  is  a  ribbon-shaped  spirillum. 
When  sulphur  granules  are  found  in  the  protoplasm  of  the 
organism,  it  is  called  an  ophidomonas. 

Several  higher  forms  of  bacteria  also  are  recognized.  They 
approach  the  plant  in  structure  and  method  of  growth. 
Among  these  is  the  streptothrixy  the  only  form  which  is  en- 
countered in  animal  pathology.  The  Streptothrix  actinomyces 
(ray  fungus)  (Fig.  8)  is  the  type  of  this  class.     The  tubercle 


CLASSIFICATION.  25 

bacillus  and  the  diphtheria  bacillus  are  included  by  some 
authorities  in  this  class.  The  streptothrix  presents  true 
dichotomous    branchings    and    forms    very     finely    tangled 

Fig.  8. 


Actinomyces,    x  250. 

masses.  In  the  course  of  its  growth  many  stages  of  the  germ 
are  seen.  Occasionally  the  filaments  break  up  and  resemble 
chains  of  bacilli  or  cocci,  or  the  free  ends  of  the  filaments 
form  club-shaped  masses,  which  may  be  an  evidence  either 
of  degeneration  or  sporulation. 

Depending  upon  their  environment  and  habits,  bacteria 
are  divided  into  saprophytes  and  parasites. 

Saprophytes  feed  only  on  dead  organic  matter,  and  usually 
are  not  disease-producing  bacteria,  unless  by  absorption  of 
the  poisonous  products  formed  by  them  from  the .  breaking- 
down  proteids. 

Parasites  always  feed  on  living  organic  matter. 

An  organism  may,  however,  be  both  parasitic  and  sapro- 
phytic, but  a  saprophytic  existence  precludes  parasitism. 

According  to  the  results  of  their  vital  activity,  bacteria 
are  pathogenic  and  non-pathogenic. 

A  pathogenic  organism  is  one  which  is  capable  of  producing 
disease. 

A  non -pathogenic  organism  does  not  of  itself  produce  disease. 

Pure  saprophytes  are  always  non-pathogenic  germs;  whereas 
parasites  are  usually  pathogenic. 

The  terms  obligative  and  facultative  are  used  to  express 
the  absence  or  presence  of  the  ability  of  accommodation  to 
surroundings.  For  example,  organisms  which  may  be  either 
saprophytic  or  parasitic  are  said  to  be  facultative  (typhoid 
and  cholera  bacilli).  Obligative  bacteria  are  those  which 
must  be  either  one  or  the  other ;  as,  for  instance,  the  lepra 
bacillus,  which  is  a  strict  or  obligative  parasite. 


26  MORPHOLOGY  OF  BACTERIA. 

According  to  the  products  of  their  metabolism,  bacteria 
may  be  classified  as  : 

Aerogenic — gas-producers. 

Zymogenic — ■fermentative  h  acteria. 

Saprogenic — putrefactive  bacteria, 

Chromogenic — color-producers. 

Photogenic — pJiosphorescent  bacteria. 
Migula  recently  proposed  a  classification  of  bacteria  which 
is  based  on  their  morphology.  Although  this  classification 
is  technically  correct,  yet  it  is  hardly  wise  to  adopt  it  at  this 
time.  It  is  too  radical  a  departure  from  the  classification 
now  in  use ;  and,  furthermore,  with  the  more  advanced  study 
of  bacteria  and  our  increasing  knowledge  of  the  subject  it 
can  safely  be  assumed  that  still  further  changes  in  the  classifi- 
cation will  become  necessary.  For  the  present,  therefore,  we 
would  recommend  the  usual  nomenclature. 
Migula's  classification  is  as  follows  : 

FAMILIES. 

I.  Cells  globose  in  a  free  state,  not  elongating  in 
any  direction  before  division  into  one,  two, 

or  three  planes 1.  Coccacece. 

II.  Cells  cylindrical,  longer  or  shorter,  and  divid- 
ing in  only  one  plane,  and  elongating  to  twice 
the  normal  length  before  division  : 

1.  Cells  straight,   rod-shaped,   without  sheath, 

non-motile  or  motile  by  means  of  flagella.    2.  Bacteriacece, 

2.  Cells  crooked,  without  sheath 3.  SpirillacecB. 

3.  Cells  enclosed  in  a  sheath 4.  Chlamydobacte- 

riacece. 

4.  Cells    destitute    of    a    sheath,    united    into 

threads,  motile  by  means  of  an  undulating 

membrane 5.  BeggiatoacecB. 

Genera. 
1.  Coccacem. 
Cells  without  organs  of  motion  : 

a.  Division  in  one  plane 1 .  Streptococcus. 

b.  Division  in  two  planes 2.  Micrococcus. 

c.  Division  in  three  planes 3.  Sarcina. 

Cells  with  organs  of  motion  : 

a.  Division  in  two  planes 4.  Planococcus. 

b.  Division  in  three  planes 5.  Planosarcina. 


CLASSIFICATION,  27 

2.  BacteriacecB. 

Cells  without  organs  of  motion 1.  Bacterium. 

Cells  with  organs  of  motion  (flagella)  : 

a.  Flagella  distributed  over  the  whole  body   .    .  2.  Bacillus. 

b.  Flagella  polar    . 3.  Fseudomonas. 

3.  Spirillacem. 

Cells  rigid,  not  snake-like  or  flexuous  : 

a.  Cells  without  organs  of  motion 1.  Spirosoma. 

b.  Cells  with  organs  of  motion  (flagella)  : 

1.  Cells  with  one,  very  rarely  two  or  three 

polar  flagella 2.  Microspira. 

2.  Cells  with  polar  flagella-tufts     .....   3.  Spirillum. 
Cells  flexuous 4.  Spirochceta. 

4.   ChlamydobacteriaceoR. 

Cell  contents  without  granules  of  sulphur: 
a.  Cell-threads  unbranched: 

I.  Cell-division  always  in  only  one  plane    .    1.  Streptothrix. 
II.  Cell-division  in  three  planes  previous  to 
the  formation  of  conidia : 

1.  Cells  surrounded  by  a  very  delicate, 

scarcely  visible  sheath  (marine)     .    .  2.  Phragmidiothrix. 

2.  Sheath  clearly  visible  (in  fresh  water)  3.  Crenothrix. 
h.  Cell-threads  branched      4.  Cladothrix. 

Cell  contents  containing  sulphur  granules   ....  5.  Thiothrix. 

5.  BeggiatoacecB. 

Only  one  species  known  [Beggiatoa  Trev.),  which 
is  scarcely  separable  from  Oscillana. 


CHAPTER  II. 

BIOLOGY  OF  BACTEEIA. 

Distribution  :  When  beginning  the  study  of  bacteriology  the 
student  is  rather  inclined  to  scoff  at  the  statement  that  bac- 
teria can  be  found  everywhere.  This  skepticism  frequently 
breeds  carelessness  on  his  part,  necessitating  much  extra  work. 
It  is  well,  therefore,  to  begin  one's  study  with  the  firm  convic- 
tion that,  no  matter  how  careful  he  is,  it  is  still  possible  for 
contamination  to  occur.  Bacteriologic  technique  is  tedious  and 
time  is  precious,  hence  the  student  will  do  well  to  ^^make 
haste  slowly".  The  cultivation  at  this  time  of  habits  of 
carefulness,  thoroughness,  and  cleanliness  will  save  him  much 
worry  and  many  sleepless  nights  in  later  life,  when  he  may 
have  ample  opportunity  to  observe  and  become  cognizant  of 
the  ever-present  bacteria. 

Bacteria  are  found  in  the  air,  in  water,  in  the  ground,  and 
in  all  kinds  of  food  and  drink.  The  surface  of  the  body 
invites  the  lodgement  of  both  pathogenic  and  non-pathogenic 
bacteria,  and  some  varieties  even  penetrate  the  protecting 
surface  epithelium.  This  is  of  importance  to  the  surgeon, 
and  enforces  the  oft-repeated  admonition  of  the  bacteriologist, 
that  the  hands  of  the  operator  should  receive  most  careful 
attention  prior  to  an  operation  in  order  to  assure  even  a  modi- 
cum of  safety  and  freedom  from  infection  of  fresh  wounds. 
The  various  cavities  which  lead  into  and  out  of  the  body  also 
contain  a  diversified  flora.  Under  normal  conditions  the 
body-juices  and  -tissues  are  entirely  free  from  bacteria.  By 
means  of  cultures  it  can  readily  be  demonstrated  that  the 
walls  and  floors  of  rooms,  and  especially  hospital  wards,  are 
never  free  from  bacteria.  Fortunately  most  of  them  are  not 
pathogenic  organisms.  It  is  well  for  us  all  constantly  to  bear 
in  mind  this  universality  of  bacteria.     It  will  account  for  the 


CONDITIONS  INFLUENCING   GROWTH  OF  BACTERIA.    29 

otherwise  inexplicable  contamination  of  cultures  in  the  labora- 
tory. 

Conditions  influencing  the  growth  of  bacteria :  It 
is  evident  from  the  foregoing  that  certain  conditions  are 
necessary  for  the  development  of  bacteria  and  the  manifesta- 
tion of  their  presence.  We  will  consider  these  requirements 
separately. 

Oxygen  :  Most  bacteria  require  oxygen.  Some  will  develop 
only  when  there  is  not  even  a  trace  of  oxygen  present ;  while 
others  can,  in  a  measure,  accommodate  themselves  to  sur- 
rounding conditions  (facultative).  In  accordance  with  their 
affinity  for  oxygen,  bacteria  are  divided  into :  aerobes^  those 
which  require  oxygen ;  and  anaerobes^  those  which  do  not 
require  oxygen  ;  further,  there  are  the  facultative  and  obliga- 
tive  aerobes  and  anaerobes.  The  following  examples  will 
serve  to  illustrate  : 

Obligative  aerobe — Bacillus  mbtilis. 
Obligative  anaerobe — Bacillus  tetani. 
Facultative  anaerobe — Bacillus  typhoms. 

Light :  Most  bacteria  are  not  influenced  by  ordinary  light ; 
but  the  direct  rays  of  the  sun  or  reflected  light  either  kill 
bacteria  or  retard  their  development.  The  same  is  true  of 
the  electric  arc  light.  A  blue  light  materially  interferes  with 
the  life-processes  of  bacteria.  The  virulence  of  pathogenic 
bacteria  is  reduced  if  they  are  grown  in  the  light.  Some  of 
the  color-producing  bacteria,  however,  will  not  produce  their 
pigment  unless  the  culture  is  exposed  to  the  light.  Some 
cultures,  on  the  other  hand,  must  be  kept  in  the  dark. 

Electricity :  The  electric  current  checks  bacterial  develop- 
ment. The  effect  of  the  Roentgen  ray  on  bacteria  is  still  a 
matter  of  speculation  ;  and  further  study  and  experimentation 
are  necessary  before  any  positive  statements  can  be  made  as 
to  its  influence  on  bacterial  activity.  The  Roentgen  ray  and 
direct  sunlight  are  being  used  in  the  treatment  of  pulmonary 
tuberculosis,  but  the  results  are  still  sub  judlcm.  The  use  of 
the  Roentgen  ray  in  cancer  is  attended  apparently  by  very 
good  results;  but  it  is  still  an  open  question  whether  or  not 
this  disease  is  of  bacterial  origin. 

Water :  All  bacteria  require  a  certain  amount  of  moisture. 


30  BIOLOGY  OF  BACTERIA. 

The  amount  needed  varies  considerably,  and  a  few  bac- 
teria possess  wonderful  accommodative  powers  in  this  respect. 
They  can  grow  on  bread  which  contains  only  a  trace  of 
moisture.  In  laboratory  work  it  will  be  found  that  bacteria 
develop  most  rapidly  in  liquid  culture-media.  Solid  culture- 
media  must  contain  at  least  80  per  cent,  of  water.  Many 
bacteria  will  grow  in  ordinary  water  provided  it  contains 
some  organic  matter,  even  if  it  is  only  a  trace. 

Nutriment :  Inasmuch  as  only  a  few  bacteria  contain  chlo- 
rophyll, it  is  absolutely  necessary  that  their  food  contain 
organic  matter.  In  the  case  of  a  few  bacteria  only  a  very 
slight  amount  of  organic  matter  is  required,  but  as  a  rule 
a  great  deal  is  necessary.  Carbon  and  nitrogen  must  be 
constituents  of  all  culture-media,  although  a  few  organisms 
can  obtain  these  elements  from  the  ammonium  salts.  When 
characteristic  growths  are  wished  for,  the  carbon  and  nitrogen 
must  be  supplied.  By  cultivating  bacteria  on  different  media, 
it  will  be  seen  that  many  bacteria  exhibit  a  decided  preference 
for  a  certain  medium.  This  is  an  important  feature  in  the 
differentiation  of  species.  It  is  possible,  however,  by  frequent 
transplantation  to  accustom  an  organism  to  a  certain  medium, 
but  this  is  done  at  the  loss  of  its  characteristic  appearance 
and  growth.  Bacteria  which  grow  very  poorly  or  not  at  all 
on  an  ordinary  culture-medium,  will  develop  luxuriantly  on 
media  to  which  a  little  glycerin  or  glucose  has  been  added. 

Reaction  :  With  a  few  exceptions  the  culture-medium  should 
be  either  neutral  or  faintly  alkaline.  An  excessively  alkaline 
or  an  acid  medium  inhibits  bacterial  development.  A  very 
few  germs  require  either  a  decidedly  alkaline  or  a  slightly  acid 
medium.     Moulds  thrive  best  in  an  acid  medium. 

Movement :  It  is  a  well-known  fact  that  a  rapidly  flowing 
body  of  water  will  purify  itself.  The  same  is  true  of  bac- 
teria in  culture.  A  slight  to-and-fro  movement  does  not 
interfere  with  their  development,  but  a  violent  shaking  either 
hinders  or  prevents  their  growth.  This  is  an  important 
factor  in  the  purification  of  rivers  w^hen  sewers  empty  directly 
into  them.  By  creating  a  rapid  current  the  growth  of  the 
contained  germs  is  checked  and  the  water  again  becomes 
pure. 


PRODUCTS  OF  BACTERIAL  ACTIVITY.  31 

Temperature  :  It  is  impossible  to  establish  an  exact  average 
temperature  limit.  As  a  rule  bacteria  will  not  develop  in 
a  temperature  lower  than  10°  C,  or  higher  than  40°  C. 
Exceptional  germs  will  grow  very  feebly,  or  possibly  only 
retain  their  vitality,  in  a  temperature  as  low  as  6°  C.  and  as 
high  as  70°  C.  A  temperature  of  10°  C.  will  inhibit  the 
growth  of  many  bacteria,  but  will  not  kill  them.  Some 
germs  safely  withstand  freezing.  Eavenel  exposed  anthrax 
spores,  diphtheria  and  typhoid  bacilli,  and  Bacillus  prodigiosus 
to  liquid  air  ( — 312°  F.)  for  from  three  hours  to  thirty  min- 
utes, and  when  the  spores  and  germs  were  transplanted  to 
bouillon  they  grew  with  their  customary  rapidity.  A  tem- 
perature over  60°  to  70°  C.  is  fatal  to  most  bacteria.  Spores 
are  more  resistant,  but  are  killed  in  boiling  water  in  a  few 
minutes.  They  will  withstand  dry  heat  (150°  C.)  for  hours. 
The  non-pathogenic  bacteria  are  better  able  to  accommodate 
themselves  to  temperature  extremes  than  the  pathogenic 
germs,  all  of  which  develop  best  at  the  body  temperature. 

Association :  The  influence  of  one  species  of  bacteria  upon 
the  growth  of  another,  when  associated  with  it  in  culture,  is  a 
matter  of  considerable  interest  as  well  as  importance.  Such 
association  will  at  times  increase  or  diminish  the  virulence 
of  pathogenic  germs.  The  toxin  of  the  streptococcus  is  much 
more  virulent  when  obtained  from  a  combined  culture  of 
Streptococcus  pyogenes  and  Bacillus  prodigiosus.  On  the  other 
hand,  the  virulence  of  anthrax  is  diminished  when  the  germ  is 
associated  in  culture  with  the  Bacillus  prodigiosus,  Sana- 
relli^s  bacillus  of  yellow  fever  grows  better  when  associated 
with  certain  moulds. 

Products  of  bacterial  activity:  In  both  the  animal 
and  the  vegetable  world  the  result  of  metabolism  is  certain 
waste  products  and  substances  which  are  necessary  to  support 
life.  Some  of  these  waste  products  are  highly  injurious. 
The  products  of  bacterial  activity  are  many,  some  of  them 
inert,  and  others  more  or  less  toxic. 

Pigment :  Those  bacteria  which  produce  pigment  are  said 
to  be  chromogenic.  The  pigment  may  be  of  any  shade.  The 
most  beautiful  colors  are  produced,  and  attempts  are  now 
being  made  to   utilize  these  pigments  commercially.     These 


32 


BIOLOGY  OF  BACTERIA. 


pigments  are  the  result  of  bacterial  action  on  the  albumins 
and  peptones.  Some  pigments  are  soluble  in  water  and 
others  are  not.  Therefore  we  may  see  either  the  entire 
medium  colored  or  only  a  portion  of  it ;  the  bacteria  them- 
selves are  free  from  pigment.  It  has  already  been  men- 
tioned that  some  germs  produce  pigment  only  in  the  presence 
of  light  and  others  only  in  its  absence.  Oxygen  appears  to 
be  necessary  for  color-production.  Some  bacteria  produce 
more  than  one  pigment.  The  Bacillus  pyocyaneus  produces 
a  blue  and  a  green  pigment ;  one  is  soluble  and  the  other  is 
insoluble.  High  temperatures  check  color-production.  The 
reaction  of  the  media  modifies  the  shade  of  the  pigment. 

Fig.  9. 


Fermentation-tube  on  left  side,  ordinary  tube  on  right  side. 

Phosphorescence :  Some  bacteria  exhibit  strong  phospho- 
rescence in  culture.  They  are  designated  as  photogenic  bac- 
teria. Most  of  these  varieties  are  found  in  sea-water.  Suf- 
ficient illumination  may  be  caused  by  a  single  culture  to 
enable  one  to  tell  the  time  by  the  watch  in  a  dark  room. 
Sea-water  gelatin  is  the  best  culture-medium.  The  Bacillus 
phosphorescens  is  the  type  of  this  group. 

Gases:  Certain  bacteria  produce  gases  as  the  result  of 
decomposition  and  fermentation.  These  gases  are  not  detected 
unless  searched  for  by  special  methods.  The  most  common 
gases  are  CO2,  CH^,  HgS,  NH^.  Gas-production  is  deter- 
mined by  the  use  of  the  fermentation-tube  (Fig.  9).    The  tube 


PRODUCTS  OF  BACTERIAL  ACTIVITY.  33 

is  filled  with  sterilized  glucose-bouillon  and  inoculated.  Any 
gases  which  may  form  will  accumulate  at  the  top  of  the  arm 
of  the  tube.  The  usual  precautions  are  taken  to  prevent 
escape  of  the  gas,  so  that  an  accurate  reading  may  be  made. 
To  determine  the  presence  of  CO2,  add  sodium  hydroxide 
and  shake ;  the  two  will  combine  and  the  difference  between 
the  original  amount  of  gas  and  the  amount  now  present  is 
the  amount  of  CO2.  Hydrogen  gas  is  detected  as  follows : 
Allow  the  gas  in  the  long  arm  to  diffuse  into  the  bulb,  mix 
with  air,  remove  the  plug,  and  apply  a  match.  An  explosion 
indicates  hydrogen  or  marsh  gas.  In  peptone-bouillon  con- 
siderable H2S  is  produced,  which  is  detected  easily  by  the 
odor.  The  presence  of  gases  may  also  be  determined  by 
adding  a  little  glucose  or  dextrose  to  nutrient  agar.  If  gas 
is  formed,  the  agar  will  be  split  into  chunks. 

Odors :  In  addition  to  the  odors  caused  by  the  gases  men- 
tioned above,  a  number  of  very  characteristic  odors  are  per- 
ceptible in  cultures.     Many  of  them  are  unpleasant. 

Aromatics  :  The  most  important  aromatic  produced  is  indol, 
as  it  is  one  of  the  means  of  differentiating  the  typhoid  from 
the  colon  bacillus.  Other  aromatics  are  skatol,. phenol,  and 
ty  rosin. 

Liquefaction  of  gelatin :  Many  pathogenic  and  non-patho- 
genic bacteria  liquefy  gelatin  by  the  production  of  digestant 
substances,  such  as  trypsin.  Anything  that  interferes  with 
the  development  of  the  germ  prevents  liquefaction.  For  in- 
stance, the  addition  of  carbolic  acid  or  glycerin  in  excess. 
When  the  bacteria  are  removed  from  the  culture  by  filtration 
the  filtrate  continues  to  liquefy.  The  liquefaction  of  gelatin 
is  a  very  valuable  aid  in  the  differentiation  of  bacteria,  as 
many  of  them  liquefy  gelatin  in  a  constant  and  characteristic 
manner. 

Fermentation:  Bacteria  produce  certain  metabolic  products  j\^ 
called  ferments,  and  the  process  by  which  these  ferments  are 
formed  is  known  as  fermentation.  Many  of  our  food-products 
are  the  result  of  fermentation  caused  by  bacteria.  The  manu- 
facture of  wine,  cheese,  butter,  and  indigo  is  largely  depen- 
dent on  such  fermentation  engendered  by  the  bacteria  which 
these  substances  harbor.     Some   bacteria  evolve   proteolytic 

3— Bact. 


34  BIOLOGY  OF  BACTERIA. 

ferments,  diastatic  ferments,  inverting  ferments,  and  rennet 
ferments.  Other  varieties  cause  lactic,  acetic,  and  butyric 
acid  fermentations.  The  well-known  alcoholic  fermentation 
is  not  due  to  bacteria,  as  was  supposed  at  one  time,  but  to  one 
of  the  yeast  fungi.  Fermentation  always  occurs  in  carbo- 
hydrates. 

Putrefaction :  This  is  analogous  to  the  fermentation  of  the 
nitrogens.  The  albumins  are  converted  into  peptones,  which 
finally  are  split  up  into  acids,  bases,  and  salts.  Putrefying  sub- 
stances give  off  a  very  foul  odor.  Putrefaction  occurs  only 
when  the  supply  of  oxygen  is  deficient  for  proper  combustion 
in  the  tissues.  Ptomaines,  indol,  skatol,  cadaverin,  phos- 
phoretted  hydrogen,  ammonium  sulphide,  and  valerianic  acid 
are  putrefactive  products.  Ice-cream  and  cheese-poisoning 
are  due  to  a  poisonous  substance  known  as  tyrotoxicon,  which 
is  produced  by  the  putrefaction  of  the  milk  proteids  before 
the  cream  or  cheese  is  made.  Other  examples  are  botulismus^ 
or  meat-poisoning,  and  fish-poisoning. 

Acids  and  alkalies :  Acids  are  formed  by  bacterial  action 
on  the  sugar  contained  in  the  media.  Butyyic,  acetic^  and 
lactic  acids  are  examples.  Ethyl  alcohol,  aldehydes,  and 
acetone  are  produced  in  less  quantity.  As  the  formation  of 
the  acid  continues,  the  growth  of  the  bacterium  is  checked 
and  finally  inhibited  completely.  By  adding  a  little  blue 
litmus  solution  to  sterile  milk,  acid-production  is  manifested 
by  the  changing  of  the  blue  color  to  red.  Rosolic  acid  changes 
the  red  to  orange.  When  alkalies  are  formed,  they  usually 
combine  with  the  acids  to  form  salts,  and  it  is  more  difficult 
to  detect  them  than  the  acids.  The  beef-extract  used  in  the 
preparation  of  culture-media  contains  a  slight  amount  of 
grape-sugar. 

Reduction  of  nitrates :  The  nitrifying  bacteria^form  nitrite^ 
from  nitratfiS*  nitrogen,  and  ammonia.  Others  form  nitrates 
directly  from  nitrogen  and  ammonia ;  and  still  another  group, 
which  is  found  in  the  soil,  oxidizes  ammonia  into  nitrites  and 
these  into  nitrates.  This  nitrification  is  of  considerable 
importance  to  the  horticulturist.  Some  bacteria  assimilate 
nitrogen  and  combine  it  so  as  to  furnish  nourishment  for 
animals  and  vegetables.     Sterile  ground   is  fertilized  in  this 


PRODUCTS  OF  BACTERIAL  ACTIVITY.  35 

way.  The  farmer  turns  under  with  the  plow  a  few  crops  of 
clover,  which  decompose  and  liberate  nitrogen.  This  free 
nitrogen  is  acted  upon  by  the  nitrifying  bacteria,  especially 
the  nitromonas,  an  organism  isolated  and  described  by  Wino- 
gradsky.  Most  of  the  nitrifying  bacteria  are  non-pathogenic 
saprophytes. 

Enzymes :  Bacteria  produce  certain  substances  known  as 
enzymes,  which,  according  to  some  authorities,  play  a  very 
important  part  in  the  production  of  immunity.  They  have  a 
decided  bacteriolytic  action,  and  are  perhaps  responsible  for 
the  phenomenon  of  agglutination.  The  limited  course  run 
by  every  infectious  disease  is  supposed  to  be  due  to  the  bac- 
teriolytic action  of  these  enzymes.  They  are  called  nucleases. 
For  instance,  typhoid  nuclease  would  be  referred  to  as  typhase, 
for  short,  etc. 

Peptonization  of  milk :  Milk  may  be  said  never  to  be  free 
from  bacteria,  and  it  is  nearly  always  impossible  to  detect 
their  presence  by  simple  inspection,  as  the  appearance  of  the 
milk  may  not  be  changed.  Some  bacteria  digest  the  casein 
without  altering  the  appearance  of  the  milk.  Others  produce 
coagulation  ;  others,  gelatinization.  The  milk  may  be  trans- 
formed into  a  watery  fluid.  Ptomaines  may  be  formed,  which 
give  rise  to  poisoning,  e.  g.,  that  due  to  tyrotoxicon. 


CHAPTER    III. 

CULTIVATION  OF  BACTERIA— PREPARATION  OF  MEDIA. 

In  order  that  bacteria  may  be  studied  properly,  it  is  neces- 
sary that  we  have  some  means  at  our  command  by  which  we 
can  observe  the  growth  and  development  of  the  individual 
organism  and  note  its  cultural  characteristics.  For  this  pur- 
pose they  are  grown  on  media  having  a  standard  composition 
and  one  which  is  most  suitable  for  observation. 

A  great  variety  of  different  media  has  been  proposed ;  but 
it  is  necessary  to  mention  only  those  which  are  the  most  useful 
and  which  may  be  used  for  general  work  in  any  laboratory. 
In  the  preparation  of  a  medium,  the  aim  must  be  to  approxi- 
mate the  body-juices  as  nearly  as  possible.  The  best  media  are 
those  which  can  easily  be  liquefied  and  solidified,  since  these 
permit  of  the  most  accurate  observation.  All  media  must 
contain  at  least  80  per  cent,  of  water.  The  reaction  should 
be  neutral  or  slightly  alkaline.  Some  bacteria  require  a 
special  culture-medium ;  and  this  will  be  described  later 
when  such  organisms  are  considered. 

Bouillon  or  Beef- tea :  This  is  the  most  easily  prepared  and 
the  most  useful  of  all  the  media  used  in  the  laboratory.  It 
also  forms  the  basis  of  nutrient  gelatin  and  agar-agar.  It 
can  be  prepared  from  chopped  beef  or  from  the  extract,  which 
is  more  convenient  and  answers  all  practical  purposes : 

Beef-extract  (Liebig),  2  grams  ; 

Dried  peptone  (powdered)  (Witte),    10       " 
Sodium  chloride  (table  salt),  5       " 

Distilled  water,  1000  c.c. 

Mix  the   beef-extract    with  a  little   water   until   it  is   thor- 
oughly  dissolved.      Add    the    peptone   gradually,   avoiding 

36 


BOUILLON  OR  BEEF-TEA.  37 

clumping.  Then  stir  in  the  salt  and  add  the  rest  of  the 
water.  Boil  for  fifteen  minutes  ;  test  the  reaction  with  litmus- 
paper  (it  is  always  slightly  acid  because  of  the  acid  in  the 
meat-extract),  and  alkalinize  with  a  saturated  solution  of 
sodium  bicarbonate  or  sodium  hydrate,  adding  the  solution 
drop  by  drop  until  the  bouillon  is  neutral  or  faintly  alkaline. 
The  mixture  should  be  stirred  constantly.  As  soon  as  the 
mixture  is  cold  it  is  ready  to  be  filtered.  It  should  never  be 
filtered  while  hot,  as  it  will  be  cloudy  because  of  the  precipi- 
tated meat-salts.  Fold  the  filter-paper  and  moisten  it  with 
hot  water  before  using.  Pour  the  bouillon  on  the  paper 
slowly  so  as  not  to  break  the  filter.  If  the  filtrate  is  cloudy, 
it  should  be  filtered  again  until  it  is  perfectly  clear.  If  the 
solution  is  too  alkaline,  it  will  be  cloudy.  The  alkalinity 
can  be  reduced  by  the  addition  of  a  little  hydrochloric  acid  ; 
but  it  is  better  not  to  do  this,  as  too  much  manipulation  is 
very  apt  to  interfere  with  the  usefulness  of  the  medium. 
Enough  water  should  be  added  to  replace  that  lost  by  evapo- 
ration. 

The  liquid  is  then  filled  into  sterile  test-tubes,  about  1 0  c.c. 
in  each  tube,  and  each  tube  plugged  with  a  cotton  stopper. 
The  tubes,  previously  placed  in  wire  test-tube  baskets  (Fig. 
.16),  are  sterilized  in  the  steam  sterilizer  for  fifteen  minutes 
on  each  of  three  successive  days.  This  sterilization  must 
be  carried  out  carefully,  in  order  to  prevent  contamina- 
tion from  any  bacteria  which  may  have  been  contained  in  the 
bouillon.  When  completed,  the  bouillon  should  be  of  a  light 
straw  color. 

This  method  is  subject  to  such  changes  and  modifications 
as  may  appear  necessary  or  desirable.  The  proportions  of 
the  various  ingredients  may  be  changed,  but  none  of  these 
can  be  omitted  or  displaced.  The  beef-stock  is  prepared 
from  the  meat  itself,  as  follows  :  place  500  grams  of  finely 
chopped  lean  beef  in  1000  c.c.  of  clean  water,  and  allow  this 
to  stand  on  ice  for  twenty-four  hours.  The  liquor  is  then 
decanted  and  the  beef  thoroughly  expressed  through  a  clean 
white  cloth,  and  sufficient  water  added  to  make  1000  c.c. 
Then  the  peptone  and  salt  are  added,  and  the  bouillon  is  fin- 
ished as  already  described. 


38  CULTIVATION  OF  BACTERIA. 

Some  objection  is  raised  to  the  use  of  sodium  solutions  as 
described  for  alkalinizing  the  bouillon,  as  it  is  so  easy  to  add 
too  much. 

The  reaction  may  also  be  taken  by  Schultze's  method.  He 
uses  a  0.33  per  cent,  alcoholic  solution  of  phenolphthalein 
and  sodium  hydroxide,  which  is  added  with  a  burette  until 
a  faint  red  color  appears.  This  indicates  a  faintly  alkaline 
reaction. 

The  first  method  is  certainly  less  complicated,  more  easily 
performed,  and  when  carefully  carried  out  gives  the  same 
results.  The  sodium  bicarbonate  must  be  added  slowly,  a 
little  at  a  time,  and  the  mixture  constantly  stirred  so  that 
the  soda  will  be  thoroughly  distributed. 

The  final  product  may  be  modified  by  the  addition  of  from 
1  to  3  per  cent,  of  glucose,  lactose,  or  saccharose.  This  is 
known  as  sugar-bouillon.  When  it  is  desired  to  have  a 
medium  free  from  sugar,  the  grape-sugar  contained  in  all 
meat-extracts  is  removed  from  the  bouillon  by  inoculating  it 
with  the  colon  bacillus,  which  destroys  the  sugar  by  fermenta- 
tion. After  twelve  hours  the  bouillon  is  filtered  and  the 
resulting  clear  fluid  is  free  from  sugar.  This  bouillon  can 
also  be  used  for  making  accurate  fermentation-tests,  as  the 
correct  percentage  of  sugar  can  be  added. 

Nutrient  gelatin :  Gelatin  has  the  same  nutrient  value  as 
beef-tea,  but  possesses  the  additional  advantage  of  being  solid. 
It  cannot,  however,  be  placed  in  the  incubator,  as  its  melting- 
point  is  25°  C.  It  is  made  from  the  beef-tea  stock  with  the 
addition  of  10  per  cent,  of  gelatin  : 


Beef-extract, 

Peptone, 

Salt, 

2  grams ; 
10      '' 
5      " 

Gelatin  (gold  label), 
Water, 

100      " 
1000  c.c. 

The  various  ingredients  are  dissolved  as  in  the  case  of  the 
bouillon.  The  gelatin  is  broken  up  finely  and  added.  The 
mixture  is  then  boiled  until  the  gelatin  is  completely  dis- 
solved.    It  is  well  to  stir  the  solution  constantly,  as  the  gela- 


AGAR-AGAR,  39 

tin  is  very  liable  to  burn.  If  the  gelatin  is  soaked  in  warm 
water  before  it  is  added  to  the  bouillon,  it  will  dissolve  much 
more  rapidly  when  boiled.  Neutralize  and  cool  to  60°  C. 
Take  the  whites  of  two  eggs  and  beat  them  up  thoroughly 
with  a  little  water ;  add  this  to  the  gelatin  mixture  and  stir 
well.  Boil  for  ten  minutes,  stirring  constantly.  The  whites 
of  the  eggs  clear  the  solution  by  embracing  most  of  the  im- 
purities in  their  coagulum. 

In  order  to  hasten  the  filtration  the  solution  is  filtered 
while  it  is  hot.  The  portion  that  is  not  poured  on  the  filter 
at  once  should  be  kept  hot  over  a  low  flame  until  ready  to  be 
used.  Gelatin  may  be  filtered  either  through  filter-paper,  a 
thick  layer  of  cotton,  or  a  double  layer  of  close-woven  cheese- 
cloth. A  very  rapid  way  is  to  place  the  filter-paper  in  the 
funnel,  and  then  spread  over  the  top  of  the  funnel  a  layer  of 
cheese-cloth.  As  the  solution  is  poured  on  the  cheese-cloth 
this  catches  the  coarser  particles  of  coagulated  albumin  and 
prevents  clogging  of  the  filter-paper.  The  gelatin  should  be 
clear.  Excessive  alkalinity  clouds  the  medium.  Prolonged 
boiling  prevents  solidification. 

After  filtration  the  gelatin  is  decanted  into  test-tubes,  10  c.c. 
in  each  tube,  and  sterilized  for  fifteen  minutes  on  each  of  three 
successive  days  in  the  steam  sterilizer.  After  the  last  ster- 
ilization the  tube  should  be  placed  in  the  upright  position,  so 
that  the  solidified  medium  will  have  a  flat,  horizontal  surface. 
In  warm  weather  it  is  necessary  to  add  more  than  10  per 
cent,  of  gelatin  in  order  to  keep  the  medium  solid.  Gelatin 
can  be  modified  by  the  addition  of  glucose,  glycerin,  or  blood- 
serum. 

Agar-agar :  This  is  a  Ceylonese  sea-weed  having  a  very 
high  melting-point,  and  is  suitable  for  cultures  which  must  be 
subjected  to  the  incubator  temperature  for  a  long  time.  Un- 
like gelatin,  it  cannot  be  liquefied  repeatedly  without  spoiling 
it.  Agar-agar  medium  is  the  hardest  to  prepare.  Its  prepa- 
ration is  extremely  tedious,  and  unless  the  greatest  care  is 
exercised  it  is  very  apt  to  spoil.  It  requires  constant  watch- 
ing. Its  formula  is  the  same  as  that  for  beef-tea,  plus  1  per 
cent,  of  agar-agar : 


40  CULTIVATION  OF  BACTERIA. 


Beef-extract, 

Peptone, 

Salt, 

2  grams ; 
10      " 
5      '' 

Agar-agar, 
Water, 

10      " 
1000  c.c. 

The  agar  is  chopped  very  fine  and  placed  in  hot  water  to 
hasten  its  solution.  The  other  ingredients  are  dissolved  as 
already  described  in  the  preparation  of  the  bouillon  and  gela- 
tin. The  mixture  is  boiled  until  the  agar  is  thoroughly  dis- 
solved. This  may  occur  in  half  an  hour  or  in  two  hours, 
and  during  all  this  time  the  mixture  is  stirred  steadily,  as 
agar  burns  very  rapidly.  After  it  is  all  in  solution,  neutral- 
ize, cool,  clarify  with  the  whites  of  one  or  two  eggs,  and  boil 
again  until  the  coagula  are  formed. 

Agar  filters  very  slowly  because  it  solidifies  so  rapidly. 
To  obviate  this,  the  filter  and  the  filtering  fluid  should  be 
kept  as  hot  as  possible.  A  hot-water  funnel  may  be  used  for 
this  purpose ;  or  the  filtering-stand  is  placed  in  the  steam 
sterilizer,  over  a  low  flame,  which  keeps  the  water  hot  without 
causing  it  to  boil.  Only  a  little  agar  should  be  filtered  at  a 
time,  the  remainder  being  kept  hot.  The  first  filtration  may 
be  made  through  a  finely  woven  cheese-cloth,  after  which 
filter-paper  should  be  used.  The  filtrate  should  be  perfectly 
clear  and  transparent.  If  all  the  steps  in  the  process  of  pre- 
paring the  agar  have  been  carried  out  carefully,  the  filtration 
ought  to  be  completed  in  about  half  an  hour.  Usually,  how- 
ever, it  requires  several  hours,  because  students  do  not  boil 
the  solution  sufficiently  in  the  first  place,  so  that  the  agar  is 
not  thoroughly  dissolved.  After  filtration  the  medium  is 
transferred  to  sterilized  test-tubes,  about  10  c.c.  in  each  tube, 
and  sterilized  in  the  steam  sterilizer  for  one  hour  on  that  day 
and  for  half  an  hour  on  the  next.  Agar  is  solidified  in  the 
inclined  position,  so  as  to  have  a  large  slanting  surface  for 
inoculation.  The  water  which  usually  collects  on  the  surface 
of  solid  media  must  not  be  removed.  It  prevents  the  medium 
from  drying  too  rajndly,  and  also  favorably  influences  the 
growth  of  the  bacteria. 

Glycerin-agar-agar :  Some  species  of  bacteria  will  not  grow 


SUGAR- A  GAB—BLOOD-SER  UM.  41 

on  agar  unless  from  3  to  5  per  cent,  of  glycerin  is  added 
(tubercle  bacillus).  The  glycerin  is  added  just  before  the 
medium  is  put  into  the  tubes. 

Sugar-agar :  From  1  to  5  per  cent,  of  sugar  is  added  to  the 
agar  in  solution.  This  medium  is  used  to  demonstrate  fer- 
mentation or  gas-production. 

Blood-agar :  The  surface  of  the  medium  is  smeared  with  a 
drop  of  blood  taken  from  the  finger-tip  or  ear,  or  from  the 
vein  of  an  animal.  This  medium  is  used  for  cultivating  the 
influenza  bacillus. 

Blood-serum  :  This  is  made  directly  from  the  blood.  Quite 
a  number  of  organisms  will  grow  on  blood-serum  only,  hence 
it  is  well  always  to  have  a  supply  of  this  medium  on  hand  ; 
a  few  tubes  will  suffice,  as  it  dries  up  very  rapidly.  The 
blood  may  be  obtained  from  an  abattoir.  After  the  animal 
begins  to  bleed  a  coagulum  is  soon  formed  on  the  hair  around 
the  wound.  Then  the  blood  is  allowed  to  flow  into  sterilized 
flasks,  which  are  well  plugged  with  cotton  as  soon  as  filled. 
The  blood-coagulum  acts  as  a  mechanical  barrier  to  contam- 
ination of  the  blood  by  the  bacteria  which  always  are  found 
on  the  hair  and  skin.  For  this  reason  no  blood  is  taken  until 
this  coagulum  has  formed.  As  many  flasks  may  be  filled  as 
desired.  After  a  firm  coagulum  has  formed  in  the  flasks  they 
are  placed  on  ice  for  forty-eight  hours.  The  clear  superna- 
tant fluid  is  then  removed  with  a  sterile  pipette  and  trans- 
ferred to  sterile  tubes.  Frequent  handling  is  not  advisable, 
as  it  increases  the  possibility  of  infection. 

The  method  of  sterilizing  the  tubes  containing  the  blood- 
serum  varies.  If  a  liquid  medium  is  wanted,  they  are  exposed 
to  a  temperature  of  60°  C.  on  each  of  five  consecutive  days. 
If  a  solid  medium  is  wanted,  they  are  exposed  to  a  tempera- 
ture just  below  the  boiling-point  (100°  C.)  for  one  hour  on 
each  of  two  successive  days.  The  medium  is  solidified  in 
the  slanting  position.  The  color  of  the  finished  product  is 
usually  grayish  and  opaque.  If  it  contains  many  red  blood- 
corpuscles,  it  is  of  a  reddish  color.  The  serum  may  be  ster- 
ilized either  in  Koch's  blood-serum  sterilizer  (Fig.  10)  or  in 
the  ordinary  steam-chest ;  but  the  latter  should  not  be  closed 
tightly,  because  if  the  temperature   is  raised  too  rapidly  the 


42 


CULTIVATION  OF  BACTERIA. 


serum  will  contain  air  bubbles.  Blood-serum  can  be  pre- 
served in  bottles  or  flasks  by  adding  an  excess  of  chloro- 
form. The  chloroform  is  evaporated  subsequently,  when  the 
medium  is  again  sterilized. 

Loeffler's  blood-serum:  This  is  a  mixture  of  blood-serum 
and  bouillon.  1  part  of  a  1  per  cent,  glucose-bouillon  is 
added  to  3  parts  of  liquid  blood-serum.  After  the  mixture 
is  transferred   to  test-tubes  it  is  sterilized  and  solidified  as 

Fig.  10. 


Chamber  for  sterilizing  and  solidifying  blood-serum,    (Koch.) 


described  above.  This  medium  is  used  especially  for  mak- 
ing cultures  of  the  diphtheria  bacillus. 

Alkaline  blood-serum :  This  also  is  used  for  the  diphtheria 
bacillus.  It  consists  of  100  c.c.  of  blood-serum  and  from  1 
to  1.5  c.c.  of  a  10  per  cent,  solution  of  sodium  hydrate. 

Milk:  After  perfectly  fresh  milk  has  been  skimmed,  it  is 
placed  in  test-tubes  and  sterilized.  To  determine  acid-pro- 
duction, sufficient  blue  litmus  is  added  to  color  the  milk. 
The  litmus  solution  should  always  be  freshly  prepared,  as  it 
spoils  very  rapidly. 

Dunham's  solution :  This  is   used  to  detect  the  aromatics 


POTATO.  43 

produced  by  certain  bacteria.     The  indol  reaction  is  demon- 
strated with  this  medium.     It  is  made  as  follows  : 


Sodium  chloride. 

0.5  gram ; 

Peptone, 

1 

Water, 

100     c.c. 

Mix  and  boil  thoroughly  ;  filter ;  fill  into  tubes  and  sterilize. 
The  solution  is  clear  and  colorless. 

The  indol  reaction  is  determined  as  follows :  Inoculate  a 
tube  of  Dunham's  solution  with  the  Bacillus  coll  communis 
(or  any  other  germ  producing  aromatics)  and  place  it  in  the 
incubator  for  twelve  hours.  Then  add  1  c.c.  of  a  0.01  per 
cent,  solution  of  KNO  and  10  drops  of  chemically  pure 
H2SO4.  A  pink  or  faint  red  color,  gradually  turning  to 
purple,  indicates  indol. 

Potato:  This  is  a  very  serviceable  and  easily  prepared 
culture-medium,  especially  for  the  cultivation  of  moulds. 
The  potato  is  cut  into  slices  and  cylinders.  Only  sound 
potatoes  should  be  used.  First  the  potato  is  washed  well  in 
water  and  scrubbed  with  a  small  hand-brush,  after  which  it 
is  placed  in  a  1  :  1000  mercuric  chloride  solution  for  an  hour ; 
then  it  is  washed  in  sterile  water,  and  the  skin  scraped  off 
with  a  sterile  knife.  Large  potatoes  are  cut  into  slices  about 
one-quarter  of  an  inch  in  thickness,  and  these  slices  are 
placed  in  sterile  Petri  dishes. 

The  cylinders  are  cut  with  an  apple-corer  or  a  cork-borer. 
They  are  made  about  two  inches  long  and  five-eighths  of  an 
inch  in  thickness.  The  ends  are  squared.  Each  cylinder  is 
cut  into  two  equal  parts  by  an  oblique  incision  which  will 
give  a  large  inclined  surface.  The  cylinders  are  placed  in 
test-tubes  with  the  slanting  surface  up.  Special  potato-tubes 
can  be  used,  or  an  ordinary  wide  and  short  tube,  in  the  bottom 
of  which  a  little  pledget  of  cotton  has  been  placed.  The 
special  tubes  have  a  small  chamber  in  the  bottom  formed  by 
a  constriction  of  the  tube.  These  tubes  can  be  made  in  the 
laboratory  by  heating  a  tube  and  constricting  it  w^ith  a  wire. 
Plug  the  tube  with  cotton.  Sterilize  both  the  tubes  and 
Petri   dishes   in   the   steam  sterilizer  for  one  hour,  and  the 


44  CULTIVATION  OF  BACTERIA. 

next  day  for  half  an  hour.  To  prevent  the  potatoes  from 
turning  dark,  Abbott  advises  that  the  cut  cylinders  be  allowed 
to  stand  in  running  water  for  twenty-four  hours.  Before 
sterilizing,  it  is  well  to  place  a  few  drops  of  sterile  water  in 
each  tube  to  keep  the  potatoes  moist. 

Potato-juice  :  This  is  made  as  follows :  Add  100  grams  of 
grated  potato  to  300  c.c.  of  water  and  place  on  ice  over  night. 
Express  the  juice  through  a  cloth  and  cook  for  one  hour  on  a 
water-bath.  Filter  and  add  4  per  cent,  of  glycerin.  Trans- 
fer to  tubes  and  sterilize  the  same  as  bouillon.  This  is  said 
to  be  an  excellent  medium  for  the  tubercle  bacillus. 

The  phosphorescent  bacteria  grow  best  in  a  medium  con- 
taining 2  or  3  per  cent,  of  sodium  chloride.  The  addition 
of  3  or  4  per  cent,  of  potassium  nitrate  will  demonstrate  the 
reducing  power  of  the  nitrifying  bacteria. 

Urine  can  be  used  as  a  culture-medium,  especially  for  the 
gonococcus  and  the  Micrococcus  urece. 

Fresh  eggs,  raw  or  boiled,  whites  of  eggs,  the  yelk,  bread 
paste,  hydrocele  fluid,  ascitic  fluid,  aqueous  humor,  and  many 
other  substances  and  preparations,  have  been  used  as  culture- 
media. 


CHAPTER    IV. 

STERILIZATION   AND   DISINFECTION. 

Sterilization  of  Culture-media  and  Laboratory  Apparatus. 

Because  of  the  presence  of  l)acteria  in  the  air  and  in 
rooms,  and  on  articles  of  furniture,  etc.,  a  very  important 
part  of  bacteriologic  technique  consists  in  destroying  these 
micro-organisms  by  sterilization  and  disinfection.  In  this 
way  the  contamination  of  the  culture-media  is  prevented  and 
germs  can  be  studied  in  pure  culture,  free  from  all  other 
organisms. 

Sterilization  is  accomplished  either  by  heaty  filtration^  or  the 
action  of  chemicals.  Usually  the  term  sterilization  is  intended 
to  imply  destruction  of  bacteria  by  heat.  Disinfection  means 
the  destruction  of  bacteria  by  the  use  of  chemicals.  Any 
substance  which  is  capable  of  killing  bacteria  is  called  a 
germicide.  One  which  inhibits  the  development  of  bacteria 
is  called  an  antiseptic.  An  object  is  said  to  be  sterile  when  it 
is  entirely  free  from  bacteria  and  their  spores.  An  object  is 
septic  when  it  contains  actively  growing  bacteria  or  their 
poisonous  products.     Aseptic  is  synonymous  with  sterile. 

All  bacteria  have  a  thermal  death-pointy  and  the  method  of 
sterilizing  and  time  of  exposure  are  regulated  accordingly. 
Culture-media,  fluids,  and  anything  that  can  be  subjected  to 
it,  are  sterilized  by  some  form  of  heat. 

Sterilization  by  heat:  This  is  accomplished  hy  fire; 
dry  heat  or  hot  air  ;  live  steam ;  superheated  steam,  or  steam 
under  pressure  ;  and  boiling. 

Fire :  This  form  of  sterilization  is  absolutely  certain  in  its 
results,  because  it  completely  destroys  all  infected  matter. 
Naturally  that  would  limit  its  use  considerably.  In  the  labo- 
ratory the*  scissors,  knives,  forceps,  and  inoculating  needles 
are  sterilized  by  passing  them  through  the  flame  of  a  Bunsen 

45 


46 


STERILIZATION  AND  DISINFECTION. 


burner  or  alcohol  lamp  a  few  times,  or  by  holding  them  in 
the  flame  for  a  few  seconds.  The  platinum  inoculating  needle 
is  held  in  the  flame  until  it  is  incandescent.  The  glass  handle 
should  also  be  sterilized  for  at  least  half  its  length.  Every 
time  this  needle  is  picked  up  and  before  it  is  laid  down  again 
it  should  be  sterilized.  This  is  very  important,  because  it  not 
only  insures  its  being  sterile,  but  it  also  protects  the  bacteri- 
ologist from  infection.  Steel  instruments  should  not  be  held 
in  the  flame  for  any  length  of  time,  as  it  aifects  the  temper  of 
the  metal.    They  can  be  passed  through  the  flame  a  few  times. 

Fig.  11. 


Hot-air  chamber.    (Leitz.) 


Dry  heat:  This  also  has  a  very  limited  application  ;  a  very 
high  temperature  is  required,  150°  C,  and  an  exposure  of  at 
least  one  hour.  This  will  kill  all  known  bacteria  and  their 
spores.  Its  application  is  limited  to  the  sterilization  of  glass- 
ware used  in  the  laboratory.  Articles  made  of  rubber,  wood, 
or  crockery  cannot  be  sterilized  by  dry  heat. 

The  tuhes^  dishes,  and  flasks  are  well  washed  and  scrubbed 


STEAM, 


47 


in  clean  water.  The  tubes  and  flasks  are  plugged  with  cotton 
(raw  cotton  will  do),  which  permits  of  the  entrance  of  air  but 
is  an  effectual  barrier  to  the  entrance  of  bacteria.  These 
articles  are  then  placed  in  the  dry  heat  sterilizer  for  one  hour. 
After  sterilization  the  cotton  plug  can  be  covered  with  a  sm^I 
rubber  cap  as  an  additional  safeguard  against  infection. 

The  hot-air  chamber  (Figs.  11  and  12)  is  a  single  or  double- 
walled  sheet-iron  or  copper  chest  having  a  door  on  one  side 
and  several  removable  shelves  on  the  inside.  The  top  of  the 
chest  is  perforated  by  two  holes,  in  one  of  which  is  placed  a 
thermometer  to  indicate  the  temperature  of  the  inside  of  the 
chest.     The  other  opening  is  plugged  with  cotton.     A  large 

Fig.  12. 


Dry  heat  sterilizer. 


Bunsen  burner  is  placed  under  this  chest,  which  rests  on  an 
iron  frame.  In  order  to  distribute  the  heat  evenly,  a  piece  of 
wire  gauze  is  placed  over  the  burner. 

The  articles  to  be  sterilized  are  placed  on  the  shelves 
within  the  chamber,  but  not  until  the  temperature  has 
reached  150°  C,  so  that  they  will  remain  in  the  chest  exposed 
to  that  temperature  for  one  hour.  Frequently  the  mistake  is 
made  of  counting  the  time  from  when  the  tubes,  etc.,  are 
placed  in  the  chamber  while  it  is  still  cold. 

Steam  :  All  culture-media,  woollen  and  cotton  fabrics,  wood, 
and  crockery  must  be  sterilized  by  steam.  Steam  is  very  pene- 
trating, and  is,  therefore,  a  most  effective  sterilizing  agent. 


48 


STERILIZATION  AND  DISINFECTION. 


The  Arnold  steam  sterilizer  (Fig.  13),  or  one  patterned 
after  this,  (Fig.  14)  is  used  for  this  purpose.  It  is  simple  in 
construction,  easily  used,  and  inexpensive.  An  exposure  of 
one  hour  is  sufficient  to  destroy  bacteria,  but  bacteria  which 
are  in  the  resting-spore  stage  may  resist  the  action  of  steam 
for  hours. 

As  such  a  prolonged  steaming  would  spoil  the  culture- 
medium,  this  should  not  be  exposed  to  its  action  for  such  a  long 

Fig.  13. 


STERILIZING  CHAMBER 


Arnold  steam  sterilizer. 


time  ;  and  for  that  reason  the  intermittent  ov  fractional  method 
of  sterilizing  is  used.  The  culture-medium  is  exposed  to  the 
action  of  the  steam  for  fifteen  minutes  on  each  of  three  suc- 
cessive days.  The  first  sterilization  will  kill  all  the  fully  de- 
veloped bacteria.  Any  spores  which  may  have  survived  this 
sterilization  will  develop  into  bacteria  in  the  course  of  the  suc- 
ceeding twenty-four  hours,  and  these  are  killed  by  the  next 


STEAM. 


49 


sterilization.  After  the  third  sterilization  the  medium  can 
safely  be  said  to  be  absolutely  sterile.  If  the  cotton  plugs  are 
not  removed,  the  medium  will  remain  sterile  forever,  but 
unfortunately  it  will,  in  the  course  of  time,  dry  up.  If  the 
tube  is  hermetically  sealed,  the  medium  will  remain  intact. 
Any  period  of  sterilization  should  not  be  continued  too  long, 
as  it  may  spoil  the  medium  by  preventing  its  solidification  ;  and 

Fig.  14. 


Boston  Board  of  Health  steam  sterilizer. 

undue  prolongation  of  the  first  period  may  also  inhibit  the 
development  of  the  spores,  which  will  thus  escape  the  eifect 
of  the  later  sterilizations  and  develop  afterward.  Agar-agar 
is  sterilized  only  twice,  because  it  cannot  withstand  repeated 
liquefying. 

Sterilization  by  steam  may  also  be  effected  by  exposing  the 
article  to  be  sterilized  to  the  action  of  streaming  or  live  steam 
for  one  hour,  or  for  fifteen  minutes  to  the  action  of  steam 

4— Baet. 


50  STERILIZATION  AND  DISINFECTION. 

under  a  pressure  of  two  or  three  atmospheres,  which  is  suffi- 
cient to  destroy  the  spores.  This  is  done  l>y  superheated 
steam  in  an  autoclave.  The  medium  is  placed  in  the  auto- 
clave, the  top  is  screwed  down  firmly,  and  the  escape  valve 
left  open  until  the  steam  has  displaced  the  hot  air.  The 
valve  is  then  closed  and  steam  is  generated  for  fifteen  minutes 
or  longer  if  desired  (Fig.  15).  Cooling  must  be  allowed  to 
take  place  gradually,  as  otherwise  the  cotton  plugs  will  be 

Fig.  15. 


Autoclave  for  sterilization  with  live  steam  under  pressure. 

forced  into  the  tubes  or  flasks  by  the  atmospheric  pressure. 
The  principal  objection  to  the  autoclave  is  that  the  reaction 
of  the  medium  is  altered  by  the  chemical  changes  brought 
about  by  the  excessively  high  temperature.  The  advantages 
are  rapid  and  absolute  sterilization. 
^  Filtration  :  Liquids  can  also  be  freed  from  bacteria  by  fil- 
tration. They  are  filtered  through  unc/Jazed  porcelain,  gravel, 
sandy  powdered  glass,  charcoal,  or  crushed  stone.     Porcelain  is 


PA  STE  URIZA  TION. 


51 


the  best.  Unstable  toxins  and  antitoxins,  which  are  destroyed 
easily  by  heat,  are  filtered  through  porcelain. 

The  objection  to  this  method  of  sterilization  is  that  it  is 
effective  for  a  time  only.  All  these  filters  become  clogged 
with  bacteria  in  the  course  of  a  very  short  time,  and  then  the 
bacteria  are  carried  through  en  masse. 

Before  a  new  filter  is  used,  it  should  be  sterilized  by  dry 
heat.  Filters  should  be  cleansed  thoroughly  at  least  once  a 
week.  Porcelain  filters  are  scrubbed  and  then  heated  in 
the  flame  of  a  blowpipe  or  Bunsen  burner  until  all  the  con- 
tained organic  matter  is  consumed.     As  the  organic  matter 

Fig.  16. 


Wire  test-tube  basket  (see  p.  37i. 

is  charred  the  filter  turns  black,  but  it  gradually  regains  its 
white  color  as  the  organic  matter  is  consumed.  Sand,  pow- 
dered glass,  etc.,  are  replaced  with  new  material  as  often  as 
is  necessary. 
^  Pasteurization  :  This  is  partial  sterilization  at  a  com- 
paratively low  temperature  with  an  exposure  of  two  or  three 
hours.  The  temperature  should  be  high  enough  to  destroy 
not  only  the  saprophytic  bacteria,  but  also  the  pathogenic 
bacteria,  especially  the  tubercle  bacillus  and  the  Bacillus 
typhosus.  Pasteurization  is  used  principally  for  the  steril- 
ization of  milk. 

The  milk,  contained  in  a  bottle,  is  placed  in  hot  water  at  a 


52 


STERILIZATION  AND  DISINFECTION. 


temperature  of  about  75°  C.  for  two  hours.  This  does  not 
alter  the  composition  of  the  milk,  and  it  will  keep  on  ice  for 
several  days. 

Disinfection  of  Instruments  and  Materials  Used  in  the 
Operating-room. 

The  same  care  that  is  used  in  the  laboratory  must  be 
observed  in  the  operating-room.  Everything  should  be  abso- 
lutely   sterile.     Any  instrument,   towel,  sponge,  or   ligature 

Fig.  17. 


Portable  steam  sterilizer  for  instruments. 


that  falls  to  the  floor  or  comes  in  contact  with  any  unsteril- 
ized  object  should  be  removed  at  once  and  resterilized  before 
it  is  used  again. 

Instruments  may  be  sterilized  by  dry  heat;  but  it  is  prefer- 
able to  subject  them  to  steam  or  to  boil  them  in  a  1  per  cent, 
solution  of  sodium  bicarbonate,  which  prevents  rusting  and 
does  not  dull  the  edge  of  sharp  instruments.  They  can  either 
be  placed  directly  in  the  water  or  be  wrapped  in  towels  or 
pieces  of  gauze.  As  soon  as  they  are  removed  from  the  ster- 
ilizer (Fig.  17)  they  are  immersed  in  sterilized  or  distilled 
water  or  in  a  5  per  cent,  carbolic  acid  solution.  Mercuric 
chloride  is  unsuited  for  the  disinfection  of  instruments  because 
it  dulls  the  edges  of  cutting  instruments,  and  also  deposits 
mercury  on  their  surfaces. 


CATGUT—SITE  OF  OPERATION.  53 

Catgut  can  be  sterilized  by  boiling.  One  of  the  best 
methods  in  use  at  the  present  time  is  the  cuniol  method.  The 
catgut  is  dried  first  in  the  hot-air  chamber  or  on  a  sand-bath, 
and  then  is  boiled  in  cumul  at  a  temperature  of  168°  C.  for 
one  hour,  which  kills  not  only  bacteria,  but  their  spores  as 
well.  The  cumol  is  evaporated  or  poured  off  and  the  catgut 
dried  at  a  temperature  of  100°  C  for  two  hours.  It  is  then 
transferred  with  sterile  forceps  to  sterile  test-tubes,  and  these 
are  plugged  with  cotton. 

Catgut  may  also  be  soaked  in  a  4  per  cent,  formalin  solu- 
tion for  twenty-four  hours ;  boiled  in  water  for  fifteen  min- 
utes, and  preserved  in  95  per  cent,  alcohol  to  which  are  added 
0.1  per  cent,  of  mercuric  chloride  and  5  per  cent,  of  glyc- 
erin. Formaldehyde  catgut  is  stronger  and  less  brittle  than 
the  old-fashioned  chromicized  catgut.  It  is  easily  tied  and 
the  knot  does  not  slip.  Pyoktanin  catgut  is  boiled  in  a  solu- 
tion of  pyoktanin. 

Ligatures  of  silk  and  silkworm-gut  are  boiled  in  water  or 
placed  in  sterile  test-tubes  and  sterilized  in  the  steam  steril- 
izer by  the  fractional  method  for  one-half  hour  each  time. 

Dressings  are  packed  loosely  in  a  canvas  bag  or  gauze 
wrapper,  and  sterilized  in  the  steam  sterilizer  by  the  frac- 
tional method.     The  autoclave  may  also  be  used. 

Sterile  water  and  sterile  salt  solution  should  always  be  on 
hand  in  large  quantities  in  every  modern  operating-room. 
They  are,  of  course,  sterilized  by  boiling. 

Drainage-tubes,  hand-brushes,  etc.,  are  kept  in  a  disinfect- 
ant solution.  A  5  per  cent,  carbolic  acid  solution  answers 
very  well. 

Site  of  operation :  It  is  advisable  to  begin  preparing  the 
site  of  operation  the  day  before  operating.  If  the  part  is 
covered  with  hair,  it  should  be  shaved,  then  thoroughly 
scrubbed  with  green  soap  and  water,  shaved  again,  scrubbed 
again,  washed  with  alcohol  followed  by  ether,  sterile  water, 
or  bichloride.  The  part  is  then  covered  with  a  protective 
dressing.  Recently  an  artificial  skin  has  been  devised  which 
is  recommended  very  highly  by  some  operators.  It  consists 
of  a  large  sterilized  piece  of  dental  rubber,  coated  on  one  side 
with  an  adhesive  substance.     It  is  spread  evenly  with  the 


54  STERILIZATION  AND  DISINFECTION. 

hand  over  the  site  of  operation,  the  warmth  of  the  hand  soft- 
ening the  gum  sufficiently  to  make  the  rubber  adhere  firmly 
to  the  skin.  It  is  treated  just  as  the  skin  would  be  ordina- 
rily, and  when  the  wound  is  sutured  it  is  included  in  the 
sutures.  When  the  stitches  are  removed,  it  is  pulled  off  like 
a  porous  plaster.  The  advantage  claimed  for  it  is  that  it  can 
be  sterilized  properly,  which  the  skin  cannot,  and  thus  insure 
absolute  cleanliness  of  the  wound  and  field  of  operation. 

Hands  of  operator:  The  disinfection  of  the  hands  of  the 
operator  and  his  assistants  is  a  very  important  matter,  and 
many  methods  are  in  vogue  aiming  to  procure  absolute  asepsis 
of  the  hands.  It  is  theoretically  impossible  to  do  this,  be- 
cause of  the  many  crevices  in  the  surface  epithelium  and 
under  the  finger-nails,  which  afford  secure  lodgement  to  all 
kinds  of  bacteria.  Cultures  of  pathogenic  bacteria  have  been 
obtained  from  the  skin  and  from  under  the  nails  after  the 
most  thorough  attempt  at  disinfection. 

The  method  most  employed  at  the  present  time  is  that 
recommended  by  Welch.  After  having  trimmed  and  cleansed 
the  nails  the  hands  are  washed  and  scrubbed  with  soap  and 
water,  the  water  of  as  high  a  temperature  as  can  be  borne,  for 
at  least  ten  minutes,  and  then  rinsed  in  clean  water.  They 
are  then  immersed  in  a  warm  saturated  solution  of  potassium 
permanganate  for  five  minutes,  washed  in  oxalic  acid  to 
remove  the  stain  of  the  permanganate,  and  then  in  warm 
water  or  salt  solution,  after  which  they  are  soaked  for  two 
minutes  in  a  1  :  500  mercuric  chloride  solution.  They  may 
then  be  considered  sterile.  The  hand-brush  must  be  sterile, 
and  should  be  kept  in  a  1  :  1000  biniodide  of  mercury 
solution. 

Another  method  is  to  scrub  the  hands  with  green  soap  and 
water  and  then  immerse  them  for  two  minutes  in  a  solution 
of  biniodide  of  mercury  in  methylated  spirit,  after  which  they 
are  rinsed  in  a  1  :  2000  biniodide  of  mercury  solution.  The 
objection  to  the  mercury  salts  is  that  they  crack  the  skin. 
Many  surgeons  cannot  tolerate  them  at  all,  and  for  that  reason 
the  permanganate  is  preferred.  Every  surgeon  has  a  method 
which  he  believes  the  best.  Personal  experience  will  govern 
the  choice  of  a  method. 


INFECTED    WOUNDS.  65 

Some  surgeons  favor  the  use  of  sterilized  rubber  gloves. 
The  objection  seems  to  be  that  they  obtund  the  sense  of 
touch ;  but  they  are  to  be  recommended  when  operating  on 
septic  or  suppurative  conditions.  Like  the  artificial  skin, 
they  can  be  rendered  absolutely  sterile.  A  German  operator 
has  recently  advocated  covering  the  hands  with  a  very  thin 
coat  of  a  specially  prepared  varnish. 

Infected  wounds  are  washed  thoroughly  with  sterile  water 
or  salt  solution,  dusted  with  some  antiseptic  powder,  and 
covered  with  an  antiseptic  dressing.  The  antiseptic  powder 
may  be  omitted.  Solutions  of  bichloride  and  carbolic  acid 
are  not  only  irritating,  but  they  also  form  chemical  compounds 
(albuminates)  with  the  tissues  and  discharges,  which  constitute 
a  protective  l^arrier  for  the  organisms  beneath  and  render  the 
antiseptic  value  of  the  solution  nil.  Strong  solutions  interfere 
with  the  healing  of  the  wounded  tissues. 

Cleanliness  and  sterilization  have  in  a  large  measure  dis- 
placed antiseptic  solutions  in  the  treatment  of  fresh  and 
infected  wounds.  When  there  is  much  pus  in  an  open  wound, 
hydrogen  peroxide  may  be  used  with  benefit.  It  liberates 
oxygen,  which  in  its  nascent  state  possesses  great  germicidal 
power.  When  dressing  a  wound,  everything  that  comes  in 
contact  with  it  must  be  absolutely  sterile,  including  the  hands 
of  the  dresser. 


CHAPTER   V. 

ANTISEPTICS  AND  DISINFECTANTS. 

It  is  impossible  in  the  limited  space  at  our  disposal  to 
enter  into  a  detailed  discussion  of  the  antiseptic  value  of  all 
the  known  antiseptics.  We  will,  however,  consider  the  most 
important  and  most  commonly  used. 

Mercuric  chloride  in  a  solution  as  weak  as  1  :  30,000  restrains 
the  development  of  anthrax  spores ;  1  :  1000  kills  them  in  a 
few  minutes.  The  addition  of  5  parts  of  hydrochloric  or 
tartaric  acid  to  1  part  of  the  mercuric  salt  will  prevent 
precipitation  of  the  mercury  by  the  albumins  of  the  tissues, 
which  lessens  its  germicidal  value  considerably.  The  bacteria 
are  embraced  in  the  albuminous  coagulum  and  thus  escape 
the  action  of  the  bichloride.  A  1  :  1000  solution  kills  the 
tubercle  bacillus  in  one  minute.  Growth  of  the  pus  cocci  is 
restrained  by  a  1  :  30,000  solution  ;  1  :  1000  kills  them  in  from 
five  to  ten  minutes.  Sternberg  advocates  its  use  as  a  general 
disinfectant  in  1  :  1000  or  1  :  500  solution  for  spore-containing 
material,  and  in  1  :  5000  or  1  :  2000  for  non-sporulating 
pathogenic  bacteria. 

Potassium  permanganate,  in  5  per  cent,  solution,  kills  an- 
thrax spores  in  twenty-four  hours.  The  dilute  solutions  used 
for  irrigating  purposes  and  urethral  injections  are  absolutely 
worthless  so  far  as  their  antiseptic  action  is  concerned.  They 
are  usually  administered  hot,  and  to  the  heat  must  be  ascribed 
their  much  vaunted  value  as  germicides.  Potassium  perman- 
ganate is  decomposed  easily  by  wound  secretions. 

Silver  nitrate  destroys  anthrax  spores  in  twenty-four  hours 
in  a  1  :  10,000  solution.  Behring  says  it  is  superior  to  mer- 
curic chloride.  It  is  very  irritating,  and  combines  with  chlo- 
rides and  albumins  to  form  insoluble  silver  salts  which  have 
no  germicidal  value.  The  various  other  silver  salts  (organic) 
now  on  the  market  do  not  combine  with  the  albumins,  and 

56 


CALCIUM  HYDROXIDE-HYDROGEN  PEROXIDE.       57 

are  less  irritating  than  the  nitrate,  but  the  clinical  reports 
are  so  contradictory  that  it  is  impossible  to  determine  their 
antiseptic  value  with  any  degree  of  positiveness.  Hardly  any 
two  men  favor  the  same  compound. 

Calcium  hydroxide,  or  slaked  lime,  in  3  per  cent,  solution, 
kills  the  typhoid  bacillus  in  six  hours ;  6  per  cent.,  in  two 
hours.  By  addmg  2  per  cent,  of  milk  of  lime  containing  20 
per  cent,  of  calcium  hydroxide  to  typhoid  stools  the  bacillus  is 
killed  in  one  hour.  It  is  not  effective  against  the  tubercle 
bacillus  nor  against  anthrax  spores.  It  is  used  very  widely  as 
a  disinfectant  of  typhoid  dejecta,  and  is  far  superior  to  either 
bichloride  or  carbolic  acid  for  this  purpose.  An  excess  of  lime 
should  be  used  in  order  to  insure  perfect  results.  The  chlori- 
nated lime  from  which  the  milk  of  lime  is  made  should  con- 
tain not  less  than  25  per  cent,  of  chlorine.  It  should  always 
be  freshly  prepared,  as  it  decomposes  rapidly. 

Boric  acid  is  practically  worthless  as  a  disinfectant.  A  satu- 
rated solution  fails  to  kill  pus  cocci  in  two  hours.  It  is  a 
very  weak  antiseptic.  A  5  per  cent,  solution  failed  to  destroy 
anthrax  spores  in  five  days  (Koch).  It  is  used  very  widely 
as  a  dusting-powder  on  wounds. 

Alcohol  (absolute)  kills  the  tubercle  bacillus  after  five  min- 
utes^ exposure.  Alcohol  in  40  per  cent,  solution  kills  the  pus 
cocci  in  two  hours. 

Pyoktanin :  Many  of  the  anilin  dyes  are  germicides,  espe- 
cially blue  pyoktanin  or  methyl-violet.  The  pus  cocci  and 
anthrax  bacilli  are  killed  in  thirty  seconds  by  a  1  :  1000  solu- 
tion ;  the  typhoid  bacillus  in  thirty  minutes.  Malachite- 
green  possesses  even  greater  germicidal  value  than  pyoktanin. 
The  objection  to  these  dyes  is  that  they  stain  and  discolor 
the  tissues. 

Chlorine :  All  the  haloid  elements  are  active  germicidal 
agents.  Chlorine  combines  readily  with  hydrogen  and  liber- 
ates nascent  oxygen.  It  is  most  active  in  the  presence  of 
moisture.  A  moist  atmosphere,  containing  the  gas  in  the 
proportion  of  1  :  2500,  kills  the  anthrax  bacillus  in  twenty- 
four  hours.  In  the  proportion  of  1  :  200  it  kills  the  tubercle 
bacillus  in  an  hour. 

Hydrogen  peroxide :  The   solutions  on   the  market  are  ex- 


58  ANTISEPTICS  AND  DISINFECTANTS. 

t^eraely  variable  in  strength  and  the  results  of  their  use 
uncertain.  They  all  deteriorate  very  rapidly.  Peroxide  is 
used  principally  for  cleansing  suppurating  wounds,  as  it  pos- 
sesses the  power  of  liberating  nascent  oxygen,  which  oxidizes 
the  purulent  secretions. 

Iodoform  is  very  mildly  antiseptic  and  possesses  slight 
germicidal  power.  Its  odor  was  for  a  long  time  accepted  as 
an  evidence  of  its  antiseptic  power.  Its  action  is  due  entirely 
to  the  liberation  of  its  iodine. 

Carbolic  acid :  This  is  the  best  known  and  most  widely 
used  disinfectant.  It  is  used  in  strengths  of  from  1  to  5  per 
cent.  Like  mercury,  it  forms  insoluble  albumin  compounds 
which  interfere  with  its  penetrating  power.  By  combining 
carbolic  acid  with  an  equal  amount  of  hydrochloric  acid  its 
germicidal  power  is  increased  considerably.  Anthrax  spores 
are  destroyed  in  three  hours  if  exposed  to  a  5  per  cent,  solu- 
tion at  the  body  temperature.  The  tubercle  bacillus  is  killed 
in  thirty  seconds.  Creolin,  lysol,  trikresol,  and  similar  prepa- 
rations, possess  the  same  germicidal  power  as  carbolic  acid. 

Sulphur  is  used  very  extensively  for  the  disinfection  of 
sick-rooms  after  contagious  diseases.  It  is  used  commonly  in 
the  form  of  a  sulphur  candle,  which  is  placed  on  a  tin  pan, 
floated  in  a  basin  of  water,  and  lighted.  The  room  should  be 
closed  tightly,  so  as  to  confine  all  the  vapor.  When  pow- 
dered sulphur  is  used,  it  is  placed  on  a  bed  of  sand  or  ashes 
in  an  iron  pot  surrounded  by  water  before  ignition.  The 
action  of  the  fumes  is  much  greater  if  the  air  in  the  room 
contains  an  excess  of  moisture.  This  is  obtained  by  evapo- 
rating a  gallon  of  water  in  the  room  just  before  igniting  the 
sulphur.  Liquid  sulphur  dioxide  may  be  used.  It  vaporizes 
at  the  room  temperature. 

The  antiseptic  and  germicidal  value  of  sulphur  has  been 
much  overestimated,  and  it  is  not  used  so  extensively  as  it 
was  some  years  ago,  it  having  been  displaced  by  a  much  more 
active  agent,  viz. : 

Formaldeliyde :  One  of  the  most  active  disinfectants  and 
germicides  is  formaldehyde.  It  is  obtained  in  the  market 
under  the  trade  name  of  formalin  or  formalose,  a  40  per  cent, 
aqueous  solution  of  the  gas  formaldehyde.     The  gas  is  ex- 


FORMALDEHYDE. 


59 


tremely  penetrating,  and  is  very  irritating  to  the  mucous 
membranes.  This  limits  its  use  to  the  disinfection  of  inani- 
mate objects.  A  15  per  cent,  solution  at  150°  C.  kills  anthrax 
spores  in  one  and  a  half  hours.  Used  as  a  liquid,  it  does  not 
possess  any  advantages  over  carbolic  acid  and  similar  prepara- 
tions. When  vaporizedj  it  is  vastly  superior  to  all  other 
agents.     Robinson  found  that  it  will   penetrate  a   mattress 

Fig.  18. 


Formaldehyde  apparatus. 


and  kill  test-tube  cultures  placed  within  it.  The  gas  is  gen- 
erated rapidly  and  continuously  by  any  of  the  different  styles 
of  formalin  generators  on  the  market  (Fig.  18).  Formalin 
pastilles  can  now  be  procured  which  contain  the  product  in 
such  quantity  as  to  permit  of  its  inhalation.  It  is  also  used 
in  the  form  of  a  spray  ;  or  sheets  saturated  with  formalde- 
hyde solution  are   hung   up   in  the  tightly  closed  room  for 


60  ANTISEPTICS  AND  DISINFECTANTS. 

twelve  hours,  after  which  the  doors  and  windows  are  thrown 
wide  open  and  the  room  thoroughly  aired.  The  number  of 
sheets  required  will  depend  on  the  size  of  the  room.  In  a 
room  10  X  10  feet  two  sheets  will  suffice.  All  crevices, 
keyholes,  etc.,  should  be  packed  with  cotton,  so  that  none  of 
the  vapor  will  escape. 

Novy's  and  the  "  Central "  formaldehyde  generator,  and 
Schering^s  lamp,  are  exceedingly  simple  in  construction  and 
inexpensive.  Others,  like  Trillat's  autoclave,  are  complicated 
and  expensive.  Either  the  apparatus  is  placed  in  the  room, 
or  the  vapor  is  sent  in  through  the  keyhole  by  means  of  a 
supply-tube.  The  temperature  of  the  room  should  be  about 
21°  C.,  and  it  should  contain  sufficient  moisture. 

Sulphate  of  copper  is  an  excellent  and  at  the  same  time  a 
very  cheap  disinfectant.  It  is  not  irritating  and  has  no  odor. 
It  is  especially  valuable  for  the  disinfection  of  typhoid  stools. 
A  pound  of  the  sulphate  is  dissolved  in  2 J  gallons  of  water, 
and  a  pint  of  this  solution  is  kept  constantly  in  the  vessel 
which  receives  the  discharges  from  both  bowels  and  bladder. 
The  poison  is  destroyed  in  fifteen  minutes  if  the  infected 
material  is  mixed  thoroughly  with  the  solution. 


CHAPTER  VI. 


PKACTICAL  DIRECTIONS  FOR  DISINFECTION. 

Excreta :  It  has  already  been  pointed  out  that  mercuric 
chloride  and  carbolic  acid  when  mixed  with  typhoid  or  diar- 
rhoeal  stools,  for  the  purpose  of  disinfection,  fall  far  short  of 
producing  the  desired  result,  and  as  the  excreta  are  the  most 
common  means  for  conveying  infection  in  typhoid,  it  is  mani- 
fest that  any  disinfection  to  be  of  value  must  be  absolute. 
Excretions  and  discharges  from  the  nose,  mouth,  lungs,  or 
conjunctivae  should  be  received  in  old  rags  or  paper  napkins 
and  burnt.     Tubercular  patients  should  be  instructed  to  use  a 

Fig.  19. 


Pasteboard  boxes  for  receiving  sputa  of  tubercular  patients. 

spit-cup,  which  is  disinfected  easily  by  boiling  or  by  the 
addition  of  chemicals.  A  small  earthenware  vessel  or  the 
pasteboard  box  (Fig.  19)  recommended  by  nearly  all  boards 
of  health  are  very  practical.  These  boxes  are  placed  in  iron 
frames  and  are  removed  once  a  day  and  burnt.  They  are 
so  inexpensive  as  to  be  within  the  reach  of  everybody.     The 

61 


62  PRACTICAL  DIRECTIONS  FOR  DISINFECTION. 

metal  or  earthenware  spit-cups  are  filled  partly  with  a  0.4 
per  cent,  solution  of  chloride  of  lime  or  a  combination  of  car- 
bolic and  hydrochloric  acids. 

The  stools  and  urine  of  patients  sick  with  an  infectious  dis- 
ease, especially  typhoid,  intestinal  tuberculosis,  and  cholera, 
should  be  received  in  a  vessel  containing  sulphate  of  copper 
solution,  or  a  5  per  cent,  solution  of  chlorinated  lime,  or  20 
per  cent,  milk  of  lime.  The  excreta  are  mixed  thoroughly 
with  the  disinfecting  solution  and  allowed  to  stand  for  an 
hour  or  two  before  final  disposition  is  made  of  them.  The 
urine  should  be  regarded  with  the  same  suspicion  as  the  stool, 
and  should  be  disinfected  immediately  after  its  passage. 

Sick-room  and  hospital  wards  :  The  custom  of  placing  in 
a  sick-room  vessels  containing  disinfecting  solutions,  with 
the  expectation  of  disinfecting  the  air  in  the  room,  is 
ridiculous.  It  is  impossible  to  disinfect  a  room  while  the 
patient  is  occupying  it.  It  is  important,  however,  that  the 
ventilation  be  perfect,  so  that  there  is  a  constant  supply  of 
fresh  air  to  take  the  place  of  the  vitiated  air.  There  is  noth- 
ing more  disagreeable,  and  at  the  same  time  harmful,  than  to 
enter  a  sick-room  and  be  greeted  by  a  heavy,  foul-smelling 
atmosphere.  It  undermines  the  patient^s  vitality  and  makes 
him  unfit  to  cope  with  the  disease.  Besides,  fresh  air  is  a 
good  purifier.  If  it  is  desired  to  disinfect  the  room  while 
occupied,  the  walls,  floors,  and  ceiling  should  be  well  washed 
with  a  1  :  1000  mercuric  chloride  solution  or  a  2  per  cent, 
carbolic  acid  solution.  The  walls  may  be  rubbed  down  first 
with  fresh  bread.  For  reasons  of  cleanliness,  sick-rooms 
should  contain  as  little  furniture  as  possible,  and  no  drapings, 
curtains,  or  anything  to  which  the  contagium  can  cling. 

After  the  room  has  been  vacated  it  is  fumigated,  with  all 
its  contents,  with  sulphur  dioxide  for  twelve  hours.  At  least 
3  pounds  of  sulphur  should  be  used  for  each  1000  feet  of 
cubic  air-space.  Then  all  the  surfaces  are  washed  with 
bichloride  or  carbolic  acid  solutions,  followed  by  plenty  of 
hot  water  and  soap  and  thorough  ventilation.  Whenever 
possible,  disinfection  should  be  done  by  means  of  formalin 
vapor.  This  will  also  disinfect  the  furniture  and  any  articles 
which  were  in  the  room  during  its  occupancy  by  the  patient. 


CLOTHING,  BEDDING,   ETC. —  UTENSILS.  63 

It  is  much  more  efficient  than  any  other  method,  and  just  as 
cheap. 

Clothing,  Bedding,  etc. :  All  bedding,  clothing,  linen,  nurse's 
outer  wearing  apparel,  and  anything  that  may  have  come  in 
contact  with  the  patient  in  any  way,  should  be  disinfected. 
If  of  little  value,  it  should  be  burnt.  Otherwise  soak  in  a 
1  :  2000  bichloride  or  a  2  per  cent,  carbolic  acid  solution  for 
four  hours,  then  boil  thoroughly  for  one  hour ;  hang  the 
washing  outdoors  where  there  is  plenty  of  air  circulating,  and 
leave  it  there  for  a  day.  This  will  further  cleanse  the  cloth- 
ing and  dispel  any  odor  of  carbolic  acid  which  would  other- 
wise cling  to  it.  Sunhght  is  also  a  disinfectant.  It  is  cheaper 
to  burn  a  straw  mattress  than  to  attempt  to  disinfect  it. 
Clothing,  etc.,  can  also  be  sterilized  by  steam  if  the  proper 
apparatus  is  at  hand. 

Patient :  The  body  of  the  patient  can  be  washed  with  a 
very  mild  solution  of  bichloride.  After  each  evacuation  of 
the  bowels  the  nates  are  cleansed  with  a  cloth  or  piece  of 
gauze  wet  with  bichloride.  The  body  of  the  convalescent  is 
treated  in  the  same  way.  After  the  exanthematous  fevers  the 
entire  body  is  washed  first  in  a  hot  bichloride  solution  and 
then  anointed  with  vaselin,  plain  or  carbolated,  olive  oil,  ben- 
zol nated  lard,  or  any  other  unguent.  This  will  prevent  the 
scales  from  being  distributed  broadcast  and  lodging  on  the 
clothing  of  the  nurse,  doctor,  or  members  of  the  family,  to  be 
carried  to  others.  Such  patients  should  also  be  isolated  until 
there  is  no  longer  any  danger  of  infection. 

The  dead :  The  body  of  a  person  dead  of  an  infectious  dis- 
ease should  be  wrapped  in  a  sheet  thoroughly  saturated 
with  either  a  0.4  per  cent,  chloride  of  lime  solution,  1 :  500 
bichloride  or  a  5  per  cent,  carbolic  acid  solution.  The  body 
should  not  be  touched  by  any  one,  and  an  early  burial  is  ad- 
visable, and  should  be  insisted  upon  if  possible.  Although 
cremation  is  really  the  best  disposition  of  such  bodies,  it  is 
not  absolutely  necessary.  Esmarch  has  shown  that  when  a 
body  is  placed  in  the  soil  all  the  pathogenic  bacteria  die,  prob- 
ably because  of  the  lack  of  oxygen  or  because  decomposition 
and  putrefaction  are  inimical  to  their  development. 

Utensils :  All  the  eating  utensils,  combs,  brushes,  etc.,  used 


64  PRACTICAL  DIRECTIONS  FOR  DISINFECTION. 

by  the  patient  should  be  kept  separate  from  those  used  by  the 
family,  as  infection  doubtless  is  carried  in  this  way.  They 
should  be  kept  in  the  patient's  room.  Such  prophylaxis  con- 
stitutes no  small  part  of  the  treatment  of  an  infectious  dis- 
ease, and  the  medical  attendant  should  be  very  specific  in  his 
instructions  in  that  regard.  He  must  insist  on  their  being 
carried  out.  When  the  patient  is  nursed  by  the  family,  many 
of  the  minor  details  of  thorough  disinfection  and  prevention 
of  a  spreading  of  the  disease  are  apt  to  be  overlooked,  or 
more  often  disregarded  because  of  their  apparent  insignifi- 
cance in  the  eyes  of  the  family. 


CHAPTEE  VII. 

CULTURES  AND  THEIR  STUDY. 

A  culture  is  an  artificial  growth  of  bacteria  on  one  or 
another  specially  prepared  medium.  Any  number  of  different 
kinds  of  bacteria  may  be  contained  in  a  culture.  If  the 
growth  contains  only  one  variety,  it  is  called  a  pure  culture. 
The  objects  in  view  in  the  preparation  of  culture-media  are 
the  separation  of  bacteria  and  the  making  of  a  pure  culture, 
so  that  the  morphology  and  biology  of  each  variety  of  organ- 
ism may  be  studied  accurately.  The  disease  caused  by  any 
one  germ  may  be  reproduced  experimentally  in  the  labora- 
tory by  the  injection  of  a  pure  culture  of  the  germ  in  ques- 
tion. Until  Koch  suggested  the  use  of  solid  culture-media 
and  the  making  of  plate  cultures  it  was  impossible  to  isolate 
bacteria  and  make  pure  cultures  of  them.  Microscopic 
examination  alone  is  frequently  insufficient  for  a  positive 
identification  of  a  germ,  as  many  species  have  the  same 
morphologic  characteristics.  Hence  it  is  a  matter  of  neces- 
sity to  cultivate  these  germs  artificially,  so  that  their  cultural 
differences  may  be  observed. 

Bacteria  are  isolated  in  pure  culture  by  the  Koch  plate 
method;  Petri  dish  method  ;  or  Esmareh  roll  culture. 

The  preliminary  steps  for  making  a  pure  culture  by  any  of 
these  methods  are  as  follow^s  :  Label  three  tubes  of  gelatin  or 
agar-agar  1,  2,  3 ;  liquefy  the  medium  over  a  flame  or  in 
water  kept  at  a  temperature  of  about  40°  C.  Sterilize  the 
platinum  needle  (Fig.  20)  and  inoculate  tube  No.  1  with  a 
loopful  of  the  material  to  be  examined.  Replace  the  plug 
and  shake  the  tube  gently,  being  careful  not  to  wet  the  cotton 
plug.  Inoculate  tube  No.  2  in  the  same  manner  with  a  few 
loopfuls  obtained  from  tube  No.  1  ;  tube  No.  3  is  inoculated 
from  tube  No.  2.  This  gives  us  three  different  dilutions. 
Another  method  for  obtaining  a  pure  culture  is  to  inoculate 

5— Bact.  65 


66  CULTURES  AND  THEIR  STUDY, 

three  beef-tea  tubes,  from  each  one  of  which  a  tube  of 
liquefied  gelatin  is  inoculated.  This  complicates  the  work 
considerably,  and  errors  are  also  more  likely  to  occur  because 
of  the  frequent  transfer  of  the  material. 

When  one  tube  is  to  be  inoculated  from  another,  tube  No.  1 
is  held  between  the  thumb  and  first  finger  of  the  left  hand 
with  the  closed  end  directed  toward  the  back  of  the  hand. 
Tube  No.  2  is  held  in  the  same  manner  between  the  first  and 
second  fingers.  The  inoculating  needle  is  held  in  the  right 
hand.     The  glass  handle  of  the  needle  should  be  at  least  six 

Fig.  20. 


h 
(a)  Looped  and  (6)  straight  platinum  wires  in  glass  handles. 

inches  long,  and  the  platinum  wire  three  inches  long  and  of 
medium  thickness.  A  little  loop  is  made  in  the  free  end  of 
the  wJre.  Before  inoculating  the  tubes,  the  cotton  plugs  are 
twisted  so  that  they  can  be  removed  easily.  The  tubes 
^should  be_  .hd<^  yery  obliquelj^  as  the  air  of  the  laboratory  is 
always  laden  with  germs.  When  ready  to  inoculate,  sterilize 
the  needle,  and  with  the  ring  and  little  fingers  of  the  right 
hand  remove  the  cotton  plug  of  tube  No.  1,  take  out  a  loop- 
ful  of  material  and  immediately  replace  the  plug.  Now  re- 
move the  plug  from  tube  No.  2  as  before,  pass  in  the  platinum 
needle,  shake  gently,  withdraw  the  needle,  and  replace  the 
plug.  Sterilize  the  needle.  The  cotton  plug  is  always  held 
between  the  fingers.  It  must  not  be  laid  on  the  table  even 
for  an  instant,  because  of  the  possibility  of  contamination. 
Holding  the  plug  between  the  fingers  mentioned  leaves  the 
hand  practically  free  to  perform  the  inoculation  unhampered 
and  without  delay,  and  the  plug  is  safe  from  contamination. 
With  a  little  practice,  this  method  can  be  carried  out  with  con- 
siderable accuracy  and  rapidity.     Inoculations  should  not  be 


KOCH  PLATE  AND  PETRI  DISH  CULTURES. 


67 


made  in  a  draft  or  near  an  open  window.     They  should   be 
done  as  quickly  as  possible. 

Koch   plate    culture :    This    method    requires   considerable 
apparatus,  and  on  the  whole  is  not  so  satisfactory  as  the  two 


Fig.  21. 


Levelling-tripod  with  glass  chamber  for  plates. 

other  methods.  The  cultures  are  made  on  clean  smooth^lass 
glates,  which  are  placed  on_  ji^jeyelJiPg.  apparatus,  under  a 
sterile  glass  chamber  (Fig.  21).  The  technique  is  the  same  as 
for  the  Petri  dish  culture. 

Fig.  22. 


Petri  dish. 


Petri  dish  culture :  This  is  the  method  commonly  used. 
It  is  easily  done  and  gives  the  most  satisfactory  results  in 
every  way.  Petri  dishes  (Fig.  22)  are  glass  dishes,  about 
four  inches  in  diameter  and  about  J  inch  in  depth,  provided 


68  CULTURES  AND  THEIR  STUDY. 

with  an  accurately  fitting  lid.  These  dishes  are  washed  and 
sterilized  by  dry  heat  for  one  hour.  The  covers  should  not 
be  removed  until  the  dishes  are  ready  to  be  used.  Take 
tube  No.  1,  burn  off  the  projecting  end  of  the  cotton  plug  in 
the  flame  of  an  alcohol  lamp  or  Bunsen  burner ;  then  with 
sterilized  forceps  push  the  plug  down  into  the  tube  for  about 
an  inch.  Hold  the  end  of  the  tube  containing  the  plug  in 
the  flame  for  a  few  minutes  to  sterilize  it.     An  assistant  now 

Fig.  23. 


Colonies  in  Petri  dish. 


raises  the  lid  of  the  Petri  dish  directly  over  the  dish  about 
one  inch  (just  high  enough  to  admit  the  end  of  the  tube),  the 
cotton  plug  is  removed  with  sterile  forceps,  and  the  contents 
of  the  tube  (which  are  still  liquid)  poured  into  the  dish.  The 
cover  is  replaced  immediately  and  the  dish  moved  gently  to 
and  fro  so  that  the  medium  will  be  spread  evenly  over  the 
bottom  of  the  dish.  The  film  of  medium  in  the  dish  should 
be  sufficiently  thin  to  be  transparent,  so  as  not  to  hinder 
microscopic  examination  of  the  colonies  of  bacteria  (Fig.  23). 


PETRI  DISH  CULTURE. 


69 


This  process  is  repeated  with  each  of  the  two  other  tubes,  and 
the  dishes  labelled  1,  2,  3,  respectively.  In  dish  No.  3  the 
colonies  will  be  much  fewer  in  number  than  in  either  No.  2 
or  No.  1,  and  the  dilutions  may  be  used  for  comparison. 

Cultures  of  pathogenic  bacteria  must  be  kept  at  a  tempera- 
ture approximating  that  of  the  body.  To  attain  this  tem- 
perature,   a    special   warming-oven     or    incubator    is    used. 

Fig.  24. 


Laboratory  incubator. 


The  incubator  (Fig.  24)  resembles  the  hot-air  oven.  The 
space  between  the  walls  is  filled  with  water,  the  amount  of 
which  is  registered  by  a  water-gauge  placed  on  one  side 
of  the  box.     The  roof  is  perforated  by  three  holes,  one  of 


70  CULTURES  AND   THEIR  STUDY. 

which  is  phigged  lightly  with  cotton  so  as  to  allow  of  plenty 
of  ^circulation  of  the  air.  One  of  the  holes  is  meant  to  con- 
tain a  gas- regulating  apparatus,  which  passes  into  the  water 
in  the  jacket.     Any  good  regulator  will  answer  the  purpose 

Fig.  25. 


Showing  certain  macroscopic  characteristics  of  colonies.    (Abbott.) 

of  regulating  the  temperature  in  the  incubator.  A  thermom- 
eter passes  through  the  third  hole  into  the  inside  of  the  incu- 
bator. Incubating  ovens  are  easily  devised  in  case  of  neces- 
sity. The  vest  pocket  or  watch  pocket,  or  the  axilla,  or  the 
pocket  of  the  night  dress,  will  serve  very  nicely  as  an  incu- 
bator for  cultures  contained  in  small  metal  boxes  or  any  con- 
tainer which  is  not  easily  broken.  For  laboratory  work, 
however,  an  incubator  is  a  necessity. 


ESMARCH  ROLL   CULTURE. 


71 


The  Petri  dishes  are  placed  in  the  incubator  for  twenty- 
four  hours,  when  the  surface  of  the  medium  is  seen  to  be 
studded  with  fine  dots,  the  number  depending  on  the  degree 
of  dilution.  These  dots  or  specks  are  called  colonies.  Colo- 
nies also  develop,  but  more  slowly,  in  the  body  of  the  medium. 
Koch  found  that  when  bacteria  are  transplanted  on  a  large  flat 
surface  (Fig.  25)  they  invariably  exhibit  a  tendency  to  isolate 
themselves  and  form  colonies  which  are  characteristic  of  each 
species  of  bacteria.     The  study  of  these  colonies  is  the  first 

Fig.  26. 


Demonstrating  Booker's  method  of  rolling  Esmarch  tubes  on  a  block  of  ice. 

(Abbott.) 


step  in  the  differentiation  of  bacteria.  Each  colony  repre- 
sentsa  pure_culture  of  the  gernL,  and  from  it  the  species  is 
propagated  for  furtlier  study.  The  colonies  are  examined 
first  with  the  naked  eye  and  then  with  a  low  power  (|) 
of  the  microscope,  the  Petri  dish  being  placed  upside  down 
on  the  stage  of  the  microscope.  An  accurate  note  is  made 
of  the  appearance  of  the  colony,  its  color,  contour,  size,  etc. 
The  description  should  be  accompanied  by  a  sketch  or  photo- 
graph. 

Esmarch  roll  culture  (Fig.  26)  :  In  this  method  the  wall 
of  the  test-tube  takes  the  place  of  the  plate  or  Petri  dish. 
Roll  cultures  are  made  easily,  and  possess  the  advantage  that 


72  CULTURES  AND  THEIR  STUDY. 

frequent  handling  and  exposure  oX  the  medium  are  not 
jreq^uired.  Tubes  used  for  this  purpose  should  contain  not 
more  than_5  c.c.  of  culture-medium.  The  medium  is  lique- 
fied and  inoculated  as  in  the  preceding  method.  The  cotton 
plug  is  burnt,  pushed  down  even  with  the  mouth  of  the  tube, 
and  covered  with  a  rubber  cap.  The  tube  is  then  held  under 
cold  running  water  or  laid  on  a  block  of  ice  and  twdrled 
rapidly  between  the  fingers,  so  that  the  medium  will  solidify 
on  the  wall  of  the  tube  in  a  thin  film.  The  colonies  form 
on  the  sides  of  the  tube,  and  are  studied  in  the  same  way  as 
those  in  the  Petri  dish.  When  the  tube  is  twirled,  care 
should  be  taken  not  to  wet  the  end  of  the  cotton  plug,  so 
that  it  will  not  adhere  to  the  tube  when  the  gelatin  or  agar 
solidifies. 

Tube  cultures :  After  the  colonies  have  fully  developed, 
tubes  are  inoculated  from  them.  Any  kind  of  medium  may 
be  used,  but  it  is  customary  to  inoculate  a  set  consisting  of  a 
tube  each  of  beef-tea,  gelatin,  agar,  potato,  blood-serum,  and 
glycerin-agar.  If  the  suspected  material  is  believed  to  con- 
tain bacteria  which  will  grow  only  on  special  media,  such 
media  must  be  used ;  as,  for  instance,  in  the  case  of  the 
tubercle  bacillus,  typhoid  bacillus,  diphtheria  bacillus,  etc. 

The  tubes  and  needle  are  held  as  before,  the  platinum  wire 
being  perfectly  straight  and  without  a  loop  at  the  end.  The 
cover  of  the  Petri  dish  is  raised  slightly,  and  with  the  sterile 
needle  a  very  small  amount  of  the  colony  is  removed  and 
transferred  to  the  test-tube.  The  wire  must  not  come  in  con- 
tact with  anything  except  the  colony  and  the  medium  to  be 
inoculated. 

For  bouillon  inoculation,  or  any  other  liquid  medium,  the 
needle  is  passed  into  the  niedium  and  the  adhering  culture 
shaken  off. 

In  gelatin  the  so-called  stah  culture  (Fig.  27)  is  made.  The 
wire  is  passed  vertically  into  the  centre  of  the  medium  for 
about  half  its  length  and  is  then  slowly  withdrawn. 

Stab  cultures  are  made  principally  for  the  purpose  of 
studying  liquefaction.  The  growth  in  or  on  gelatin  is  varied, 
and  often  quite  characteristic.  Thus,  it  may  be  limited  to  the 
surface  of  the  medium;  or  to  the  stab;  or  it  may  appear  both 


TUBE  CULTURES.  73 

on  the  surface  and  along  the  stab.  Some  species  liquefy  the 
gelatin  and  others  do  not.  Some  bacteria  liquefy  the  medium 
in  a  manner  which  is  characteristic  of  the  germ. 

Gelatin  cultures  may  also  be  enihedded  2indi  sectioned:  The 

Fig.  27. 


Series  of  stab  cultures  in  gelatin,  showing  modes  of  growth  of  different  species 

of  bacteria. 

tube  is  warmed  a  little  so  as  to  loosen  the  gelatin  (without 
melting  it),  which  then  is  transferred  to  and  fixed  in  Mueller's 
fluid.  It  is  hardened  in  alcohol,  embedded  in  celloidin,  sec- 
tioned, and  stained  like  tissue  preparations.  Winkler  suggests 
filling  a  cavity  in  a  block  of  paraffin  with   sterile  gelatin. 


74  CULTURES  AND  THEIR  STUDY. 

After  it  has  solidified  it  is  inoculated.  When  the  growth  has 
developed  sufficiently,  the  entire  block  is  sectioned  under 
alcohol  and  the  sections  are  stained  with  a  weak  carbol-fuchsin 
solution.  ^ 

On  media  having  a  slanting  surface,  such  as  agar,  potato, 
or  blood-serum,  a  stroke  or  smear  culture  is  made.  For  a 
stroke,  the  wire  is  passed  in  a  straight  line  across  the  centre 
of  the  surface;  for  a  smear,  the  needle  is  rubl)ed  gently  over 
the  entire  surface.  In  neither  case  does  the  needle  penetrate 
the  medium. 

The  comportment  of  the  germ  toward  oxygen  is  noted  also. 
A  heavy  surface  growth  denotes  aerobic  tendencies.  A 
heavy  growth  along  the  line  of  inoculation  and  a  slight  sur- 
face growth  denote  anaerobic  tendencies. 

These  tubes  are  incubated  and  a  record  of  the  growth  made 
from  time  to  time.  Gelatin  tubes  and  dish  cultures  cannot 
be  placed  in  the  incubator  because  of  the  low  melting-point 
of  the  gelatin.  For  this  reason  agar  is  used  mostly  in  the 
preparation  of  the  dish  cultures. 


Fig.  28. 


/c:;-^.. 


Zoogloea  of  bacilli.    (Abbott.) 

The  membranous  pellicle  formed  by  bacteria  on  the  surface 
of  liquid  media  is  called  a  mycodei-ma.  When  the  growth 
forms  principally  in  the  mass  "or  body  of  the  medium,  gelati- 
nous-looking masses  are  formed,  the  zoogloea  (Fig.  28). 

Klatsch  preparation :  Occasionally  it  is  desirable  to  make 
a  microscopic  specimen  of  an  entire  colony.  Take  a  clean 
cover-glass,  warm  it  slightly,  and  lay  it  carefully  on  the 
colony.  A  little  pressure  will  remove  the  air  bubbles  under 
the  cover-glass  without  destroying  the  contour  of  the  colony. 
The  cover-glass  is  then  lifted  up  carefully,  when  the  colony 


ANIMAL  INOCULATION.  75 

will  be  found  to  adhere  to  it.  This  is  called  a  Klatsch  or 
adhesion  preparation.  The  preparation  is  dried,  fixed,  and 
stained  like  any  ordinary  microscopic  specimen,  as  will  be 
described  later. 

Animal  inoculation :  Pure  cultures  may  also  be  obtained 
by  animal  inoculation.  The  suspected  material  is  mixed  with 
a  small  quantity  of  sterile  water  and  injected  into  the  abdomi- 
nal cavity^  subcutaneous  tissue,  or  ear  vein  of  a  mouse  or 
gumea-pig.  This  method  is  restricted  almost  entirely  to 
obtaining  pure  cultures  of  the  tubercle  or  anthrax  bacillus. 

All  these  various  cultures  can  be  preserved  for  museum 
specimens  by  fixing  them  in  formalin,  which  is  applied  in 
the  form  of  a  spray  or  dilute  solution;  or  the  tubes  are  placed 
in  a  tightly  closed  jar  containing  a  little  dilute  formalin  solu- 
tion. After  ten  days  they  are  removed  and  the  ends  of  the 
tubes  are  sealed  in  a  flame ;  or  are  stoppered  with  a  cork  or 
wooden  plug  and  dipped  in  paraffin.  Cultures  at  diiferent 
stages  of  development  and  in  all  kinds  of  media  may  be  thus 
preserved  and  used  for  class-room  instruction.  They  make  a 
very  attractive  and  instructive  museum  exhibit. 


CHAPTER    VIII. 

CULTIVATION  OF  ANAEROBIC  BACTERIA. 

Pasteur,  as  early  as  1861,  demonstrated  that  certain 
species  of  bacteria  will  grow  only  in  the  absence  of  oxygen. 
Anaerobic  bacteria  grow  best  in  a  medium  containing  from  1 
to  2  per  cent,  of  sugar.  Various  methods  have  been  devised 
for  the  cultivation  of  these  organisms.     Some  of  them  are 

Fig.  29. 


Liborious  tube  for  anaerobic  cultures :  x  =  places  sealed. 


simple  and  others  very  complicated,  requiring  considerable 
apparatus.     A   tube  containing  at  least  20  c.c.  of  medium  is 
inoculated  while  the  medium  is  liquid.     The  anaerobic  bac- 
teria develop  in  the  body  of  the  medium. 
76 


CULTIVATION  OF  ANAEROBIC  BACTERIA. 


77 


Hesse  covers  the  surface  of  the  inoculated  medium  with 
sterile  olive  oil,  more  effectively  to  exclude  oxygen. 

Smith  fills  the  tube  with  sterile  gelatin,  thus  burying  the 
culture.  He  uses  an  ordinary  fermentation-tube  for  this  pur- 
pose.    A  test-tube  answers  as  well. 

Liborius  expels  the  air  from  the  tube  and  medium  by 
boiling.  The  liquid  medium  is  inoculated  and  then  hard- 
ened in  ice  water.  The  tube  (Fig.  29)  is  sealed  with  the 
blowpipe. 

Fig.  30. 


Fraenkel's  method  for  the  cultivation  of  anaerobic  bacteria. 

Esmarch  makes  a  roll  culture,  and  then  fills  the  tube  with 
sterile  gelatin. 

Buchner  absorbs  the  oxygen  with  pyrogalliG  acid.  1 
gram  of  pyrogallic  acid  and  10  c.c.  of  a  6  per  cent,  solution 
of  potassium  hydroxide  are  placed  in  a  large  dissolving  tube. 
The  tube  containing  the  culture  is  stood  inside  of  the  large 
tube,  which  then  is  corked  and  sealed  with  paraffin. 


78  CULTIVATION  OF  ANAEROBIC  BACTERIA. 

Roux  plants  a  strict  aerobe  (Bcwillus  subtilis)  on  the  top  of 
the  anaerobic  culture.  The  medium  is  boiled  first,  then 
quickly  cooled  and  inoculated.  The  top  is  covered  with 
sterile  gelatin  inoculated  with  the  aerobe.  The  aerobe  absorbs 
the  oxygen  and  the  anaerobe  develops  in  the  bottom  of  the 
tube  where  there  is  no  oxygen. 

Gh'uber  exhausts  the  air  in  the  tube  with  an  air-pump. 

Hueppe  inoculates  eggs  in  the  shell  through  a  very  small 
hole  made  with  a  hot  needle.  The  opening  is  sealed  with 
collodion  after  inoculation. 


Jar  for  anaeruliic  cultures. 

Fraenhel  uses  an  ordinary  test-tube  stoppered  with  a  rub- 
ber stopper  perforated  by  two  holes,  through  which  two  glass 
tubes  are  passed  (Fig.  30).  One  tube  is  short,  and  the  other 
passes  through  the  medium  to  the  bottom  of  the  test-tube. 
Both  glass  tubes  are  bent  at  right  angles  above  the  stopper 
and  drawn  out  to  a  very  small  calibre,  so  that  they  can  be 
sealed  easily.  Hydrogen  is  passed  into  the  tube  through  the 
long  glass  tube  and  escapes  through  the  short  tube.  After 
five  or  ten  minutes  the  projecting  free  ends  of  the  glass  tubes 
are  sealed  at  the  places  previously  prepared  for  that  purpose, 
and  the  entire  rubber  stopper  is  covered  with  paraffin  to  pre- 
vent entrance  of  oxygen  and  leakage  of  hydrogen. 

Novy  uses  a  large  glass-stoppered  jar  (Fig.  31)  constructed 
on  the  same  plan  as  FraenkePs  tube. 


CULTIVATION  OF  ANAEROBIC  BACTERIA.  79 

Sternberg  prepares  three  Esraarch  roll  cultures.  The  cotton 
plug  is  pushed  down  into  the  tube  for  a  short  distance.  The 
end  of  the  tube  is  closed  with  a  soft-rubber  stopper  carrying 
two  glass  tubes.  This  stopper  is  pushed  below  the  level  of 
the  tube  half  an  inch,  and  the  space  is  filled  with  melted  seal- 
ing-wax. The  test-tube  is  inverted  and  hydrogen  gas  passed 
in  through  one  of  the  tubes.  The  gas  diffuses  through  the 
cotton  plug  into  that  portion  of  the  tube  containing  the  cult- 
ure. After  a  few  minutes  the  outlet  tube  is  sealed  and  then 
the  inlet  tube.  It  is  not  necessary  to  sterilize  the  rubber 
stopper,  as  the  cotton  plug  is  interposed  between  it  and  the 
culture. 

Ravenel  places  the  culture  in  an  air-tight  chamber  par- 
tially filled  with  pyrogallic  acid  and  a  10  per  cent,  solution 
of  caustic  potash.  The  air  is  exhausted  with  an  air-pump 
and  the  chamber  is  then  hermetically  sealed.  The  chamber 
contains  an  upright  shelf-stand  on  which  Petri  dishes  are 
placed.  Any  oxygen  left  in  the  chamber,  or  which  enters,  is 
absorbed  by  the  pyrogallic  acid. 

Koch  covers  the  surface  of  a  glass  plate  containing  the  cult- 
ure with  a  mica  plate,  thus  excluding  oxygen. 

Bothin  uses  a  large  bell-jar,  which  is  stood  in  a  dish  con- 
taining liquid  paraffin.  Two  rubber  tubes  are  carried  through 
the  paraffin  into  the  jar.  Hydrogen  gas  is  then  sent  into  the 
jar  through  one  of  the  tubes,  and  when  only  pure  hydrogen 
escapes  from  the  other  the  tubes  are  withdrawn,  the  solidify- 
ing paraffin  closing  the  holes  so  that  no  oxygen  can  enter  the 
jar.  It  is  advisable  to  put  a  little  pyrogallic  acid  into  the 
jar  in  case  of  leakage. 

i?o?i.T  suggests  still  another  method.  The  medium  is  lique- 
fied and  inoculated.  While  still  liquid  it  is  drawn  into  a 
long  small-calibred  piece  of  glass  tubing,  the  ends  of  which 
have  been  slightly  drawn.  When  the  tube  is  full  the  ends 
are  sealed.  When  the  colonies  have  developed,  the  tube  is 
broken  with  a  file  or  diamond  and  the  culture  transplanted. 

Any  of  these  methods  is  subject  to  such  modification  as 
may  be  desired  by  the  individual  investigator. 


CHAPTER   IX.     , 

MICROSCOPIC  EXAMINATION   OF   BACTERIA. 

Motility  :  The  first  step  in  the  microscopic  examination  of 
bacteria  is  to  determine  whether  the  organism  is  motile.  This 
is  done  by  means  of  the  Aa92^^^7^£^ro£.  The  living  bacteria 
can  be  observed  for  days  at  a  time,  if  necessary,  in  their  char- 
acteristic grouping,  and  their  multiplication  and  formation  of 
spores  watched. 

A  cover-glass  is  cleansed  thoroughly  and  a  drop  of  sterile 
water  or  bouillon  placed  in  its  centre.  With  a  sterile  pla- 
tinum loop  some  of  the  culture  is  transferred  to  this  drop. 
The  cover-glass  is  then  inverted  over  a  glass  slide  having  a 
round  excavation  in  its  centre  (Fig.  32),  a  concave  slide.     In 

Fig.  32. 


Hanging  drop. 

order  to  increase  the  size  of  this  little  chamber,  and  also  to 
exclude  the  air  from  the  drop,  the  edge  of  the  depression  is 
rimmed  with  vaseline,  the  cover-glass  being  dropped  on 
the  vaseline.  The  drop  may  be  examined  with  a  powerful 
hand  lens  or  with  a  high-power  kns  (^  or  ^)  of  the  micro- 
scope. An  oil-immersion  lens  cannot  be  used  unless  it  is 
focussed  simply  on  the  cover-glass  without  changing  the  field. 
Any  attempt  at  changing  the  field  is  apt  to  spoil  the  drop. 
The  lens  must  be  brought  down  very  slowly,  so  as  not  to 
break  the  cover-glass.  The  iris-diaphragm  is  closed  almost 
completely,  as  the  bacteria  are  very  refractile. 

The  bacteria  are  seen  as  minute  shining  bodies  that  either 
remain  stationary  or  scamper  across  the  field  with  either  a 

80 


PREPARATION  OF  STAINS. 


81 


sinuous,  undulating,  or  rotary  movement.  It  is  impossible  to 
see  the  flagella. 

When  the  examination  has  been  completed,  the  slide  and 
cover-glass  are  dropped  into  a  5  per  cent,  carbolic  acid  solu- 
tion and  left  there  for  one  hour.  Disinfection  by  heat  is  dan- 
gerous, because  the  drop  is  very  apt  to  sputter  and  thus  be 
the  means  of  carrying  infection. 

Preparation  of  stains  :  The  anilin  dyes  are  used  almost 
exclusively  for  the  staining  of  bacteria.  Those  manufactured 
by  Gruebler  are  the  most  reliable,  and  should  always  be  spe- 
cified when  dry  stains  are  ordered.  The  most  widely  used 
stains  are  gentian-violet,  methylene-blue,  fuchsin,  vesuvin, 
and  malachite-green.  So-called  stock  solutions  of  these  stains 
should  always  be  on  hand.  From  these,  small  quantities  of 
stain  are  prepared  for  immediate  use,  as  they  deteriorate  very 
rapidly.  They  are  kept  in  small  bottles  supplied  with  stop- 
pers and  pipettes  (Fig.  33).    Vesuvin  and  malachite-green  are 

Fig.  33. 


Rack  of  bottles  for  staining  solutions. 


kept  in  1  per  cent,  aqueous  solution.  »Qf  all  the  other  stains 
alcoholic  stock  soTutrons  are  made  Aqueous  stock  solutions 
can  be  prepared  when  needed.  The  stock  solutions  are  made 
by  adding  1  part  of  the  powdered  dye  to  4  parts  of  abso- 
lute alcohol.  A  glass-stoppered  bottle  is  filled  to  one- 
quarter  of  its  capacity  with  the  dye,  and  sufficient  absolute 
alcohol  (or  water  for  aqueous  solutions)  added  to  fill  the 
bottle.  An  excess  of  the  dye  may  be  used  to  insure  satura- 
tion ;  the  excess  remains  undissolved   in  the  bottom  of  the 

6— Bact. 


82  MICROSCOPIC  EXAMINATION  OF  BACTERIA. 

bottle.  The  stains  are  prepared  from  these  stock  solutions 
by  adding  5  c.c.  of  the  solution  to  95  c.c.  of  distilled  water; 
or  the  stock  solution  is  added  to  the  water  drop  by  drop  until 
a  good  color  is  produced.  The  first  method  is  preferable,  as 
it  is  more  exact. 

Loelfler's  alkaline  methylene-blue  is  made  as  follows : 

Saturated  alcoholic  solution  of 

methylene-blue,  30  c.c. ; 

Caustic  potash  (1  :  10,000),  100    " 

This  stain  is  always  used  for  staining  the  diphtheria  bacillus. 

The  anilin-water  stains  are  prepared  as  follows :  5  c.c.  of 
anilin  oil  are  shaken  thoroughly  with  100  c.c.  of  distilled 
water.  This  solution  is  filtered  through  filter-paper  until  it 
is  perfectly  clear.  To  100  c.c.  of  the  filtrate  add  10  c.c.  of 
absolute  alcohol  and  11  c.c.  of  the  concentrated  alcoholic 
solution  of  the  stain.  The  anilin-water  stains  are  used  where 
a  very  strong  stain  is  required.  They  are  decomposed  easily, 
however,  and  should  be  prepared  in  small  quantities  only. 
The  anilin  water  may  be  kept  on  hand,  so  that  the  stain  can 
be  prepared  rapidly  when  needed. 

Staining  slides  and  cover-glasses  :  Bacteria  may 
be  examined  on  a  slide  or  a  cover-glass.  Cover-glasses, 
because  of  their  size,  can  be  placed  in  the  stain,  but  slides 
are  handled  more  easily.  They  should  be  absolutely  clean 
and  free  from  fatty  matter.  First  immerse  them  in  a  mineral 
acid  or  a  mixture  of  sulphuric  acid  and  potassium  bichro- 
mate ;  then  in  successive  washings  of  water,  alcohol,  and 
ether.  They  are  kept  in  ether  until  ready  to  be  used.  If 
desired,  they  may  be  kept  in  alcohol,  when  the  ether  washing 
is  omitted.  For  use,  they  are  wiped  dry  with  a  piece  of 
cheese-cloth  and  passed  a  few  times  through  the  flame  of  an 
alcohol  lamp  or  Bunsen  burner. 

For  convenience  we  will  consider  the  preparation  of  a  slide 
(the  cover-glass  is  prepared  in  the  same  way) : 

Spread  the  material  on  the  slide  as  thinly  as  possible. 
Students  usually  make  the  mistake  of  spreading  it  too  thick 
for  fear  that  there  is  not  sufficient  on  the  slide.     The  thinner 


TUBERCLE  BACILLUS.  83 

the  preparation,  the  better  the  result.  If  the  material  is  too 
thick  or  viscid,  a  drop  of  distilled  water  is  placed  on  the 
slide  and  the  material  gently  spread  in  this.  The  film  must 
be  dried  in  the  air,  and  not  in  the  flame.  Drying  in  the  flame 
is  more  rapid,  but  it  always  spoils  the  specimen.  If  the  film 
is  thin,  it  will  dry  rapidly.  After  it  is  thoroughly  dry,  it  is 
fixed  in  the  flame.  It  should  not  be  held  in  the  flame,  but 
passed  through  it  three  or  four  times.  This  fixes  the  bacteria 
on  the  slide  by  coagulating  the  albumin  in  them.  The  next 
step  is  to  stain  the  specimen. 

Several  different  kinds  o^  forceps  have  been  devised  to 
hold  the  slide  or  cover-glass,  but  the  wire  forceps  (Stewart) 
are  the  best.  They  hold  the  glass  securely  and  prevent  soil- 
ing of  the  fingers  or  clothing  by  the  stain.  With  the  ordi- 
nary bladed  forceps  the  stain  is  drawn  up  between  the  blades 
by  capillary  attraction,  and  then  it  is  impossible  to  keep  it 
from  staining  the  fingers. 

The  film  is  covered  well  with  the  stain,  which  is  allowed 
to  act  for  a  few  minutes.  To  facilitate  staining,  the  stain 
may  be  warmed  slightly.  Decant  the  stain  and  wash  the  slide 
in  water.  Stain  again  if  necessary.  Dry  in  the  air,  first 
removing  the  excess  of  water  with  a  blotter,  and  mount  in 
Canada  balsam.  The  specimen  is  ready  to  be  examined.  A 
^  inch  oil-immersion  lens  should  always  be  used  if  possible. 

Tubercle  bacillus  :  Special  stains  and  staining-methods 
are  necessary  for  the  tubercle  bacillus.  Many  diff^erent 
methods  have  been  devised.  The  principle  of  them  all  is  to 
use  a  stain  which  stains  so  intensely  that  it  cannot  be  removed 
from  the  bacillus  with  either  mineral  acids  or  alcohol.  The 
tubercle  bacillus  is  extremely  resistant  to  decolorizing  agents. 
The  film  is  prepared  in  the  same  manner  as  for  the  ordinary 
bacteria.  If  the  slide  is  made  from  sputum,  the  little  white 
or  yellowish  nodules  should  be  selected,  as  they  are  most  apt 
to  contain  the  tubercle  bacillus.  By  shaking  the  sputum 
with  a  5  per  cent,  solution  of  carbolic  acid  little  albuminous 
masses  are  formed.  One  of  these  may  be  selected  and  spread 
on  the  slide  as  thinly  as  possible ;  or  the  mass  is  opened  and 
only  its  centre  placed  on  the  slide.  The  utmost  care  is  neces- 
sary in    the    handling   of  tubercular   matter   or   any  matter 


84  MICROSCOPIC  EXAMINATION  OF  BACTERIA. 

which  is  suspected  of  being  tubercular.  Nothing  but  the 
needle  should  come  in  contact  with  it,  and  as  soon  as  there  is 
no  further  use  for  it  it  should  be  covered  with  a  5  per  cent, 
carbolic  acid  solution  or  milk  of  lime.  The  inoculating 
needle  should  be  sterilized  immediately  after  use,  and  like- 
wise anything  else  that  may  have  come  in  contact  with  the 
suspected  material.  The  film  is  dried  in  the  air  and  fixed  in 
the  flame  before  staining  ; 

Ehrlich-Weigert  method :  Float  the  cover-glass,  film  side 
down,  in  a  watch-crystal  containing  anilin  methylene- violet ; 
or  immerse  the  cover-glass  film  side  up.  Heat  until  the  stain 
begins  to  steam ;  then  set  it  aside  for  two  or  three  minutes. 
Remove  the  specimen  from  the  stain  and  decolorize  in  1  part 
of  nitric  acid  and  3  of  distilled  water.  Hold  the  cover-glass 
with  the  forceps  and  move  it  gently  to  and  fro  for  a  few 
seconds.  Wash  in  60  per  cent,  alcohol  and  then  in  water. 
If  a  contrast-stain  is  wanted,  cover  the  film  for  a  few  minutes 
with  a  saturated  solution  of  vesuyin.  Wash,  dry,  and  mount 
in  CanaTia  balsam.  The  tubercle  bacillus  is  stained  violet  or 
purple,  and  all  the  other  organisms,  as  well  as  the  mucus,  are 
stained  a  light  brown. 

Friedlaender  method:  The  stain  used  in  this  method  is 
known  as  ZiehPs  solution.     It  consists  of: 

Fuchsin,  1  gram ; 

Alcohol,  10  c.c. 

Dissolve,  and  add  100  c.c.  of  a  5  per  cent,  solution  of 
carbolic  acid. 

Cover  the  smear  with  this  stain  and  heat  gently  until  steam 
is  given  off.     Decolorize  with  : 

Nitric  acid,  5  c.c. ; 

Alcohol  (80  per  cent.),  95    " 

and  counter-stain  with  methylene-blue.  Wash  in  distilled 
water,  dry,  and  mount  in  Canada  balsam.  The  tubercle 
bacillus  is  stained  a  bright  red,  everything  else  blue. 

Gabbett  method:  This  is   an  exceedingly   simple  method, 


TUBERCLE  BACILLUS.  85 

the  contrast-stain  being  added  to  the  decolorizing  agent.  The 
smear  is  stained  with  ZiehFs  solution  as  before,  after  which 
it  is  immersed  for  a  few  minutes  in  Gabbett's  solution  : 

Methylene-blue,  2  grams;  \^/^ 

Sulphuric  acid  (25  per  cent. 

aqueous  solution),  100  c.c. 

Wash  in  water,  dry,  and  mount  in  balsam.  The  tubercle 
bacillus  is  stained  a  bright  red,  everything  else  is  stained  blue. 
The  objection  to  this  method  is  that  it  is  impossible  to  deter- 
mine, without  removing  the  specimen  from  the  stain  and 
washing,  just  when  decolorization  is  complete.  The  acid 
and  the  methylene-blue  may  be  used  separately. 

Ziehl-Neelson  method :  The  cover-glass  is  floated  on  the 
carbol-fuchsin  solution,  film  side  down,  for  from  three  to  five 
minutes,  or  until  it  commences  to  steam  ;  or  the  stain  is  heated 
first  and  then  poured  over  the  film  and  allowed  to  act  for  a 
few  minutes.  Decolorize  in  25  per  cent,  nitric  acid  or  sul- 
phuric acid  until  the  film  is  a  very  light  brown  or  yellow. 
Wash  in  60  per  cent,  alcohol  for  a  few  minutes,  then  water ; 
mount  in  balsam  after  drying.  A  contrast-stain  may  be  used 
if  desired. 

Ehrlich  method  :  Float  or  immerse  the  cover-glass  in  anilin- 
water  gentian-violet  and  place  it  in  the  incubator  for 
twenty-four  hours.  Wash  in  water,  and  alternately  in  33  per 
cent,  nitric  acid  and  60  per  cent,  alcohol  until  the  color  has 
almost  entirely  disappeared.  After  a  final  washing  in  the 
alcohol,  wash  in  water  and  counter-stain  with  vesuvin  or 
Bismarck-brown.  Methylene-blue  may  also  be  used.  Wash 
in  water,  dry,  and  mount  in  balsam.  The  tubercle  bacilli  are 
stained  a  dark  blue,  and  the  other  bacteria  and  the  tissue-cells 
are  colored  brown. 

Dorset  method :  Dorset  found  that  Soudan  TIL  has  a  se- 
lective action  on  the  tubercle  bacillus  because  of  the  large 
proportion  of  fat  (40  per  cent.)  contained  in  the  bacillus. 
Immerse  the  film  for  ten  minutes  in  a  cold  saturated  80  per 
cent,  alcoholic  solution  of  Soudan  III.  Remove  the  excess 
of  stain  with   successive  washings  of  70  per  cent,  alcohol. 


86  MICROSCOPIC  EXAMINATION  OF  BACTERIA. 

Wash  in  water,  dry,  and  mount.  The  tubercle  bacilli  are 
stained  a  very  brilliant  red. 

Some  experience  is  necessary  before  the  tubercle  l)acillus 
can  be  stained  satisfactorily.  Care  must  be  taken  that  the 
stain  has  acted  sufficiently,  and  that  the  decolorizing  agent  is 
not  such  in  fact.  It  is  impossible  to  overstain.  Decoloriza- 
tion  with  the  dilute  mineral  acids  is  achieved  in  thirty  seconds. 
The  film  should  always  contain  a  sufficiency  of  stain.  The 
stain  must  be  replaced  if  evaporation  occurs.  A  3  per  cent, 
alcoholic  solution  of  hydrochloric  acid  is  also  a  good  decolor- 
izer.  Spirit  of  nitrous  ether  may  be  used.  It  is  of  agree- 
able odor,  and  does  not  stain  the  hands,  nor  is  it  irritating  to 
the  mucous  membranes.  When  staining  for  tubercle  bacilli 
in  sputum  or  other  tubercular  material,  it  should  be  borne 
in  mind  that  it  is  not  always  possible  to  find  the  bacillus  in 
the  first  specimen.  Oftentimes  as  many  as  a  dozen  must  be 
made  before  it  can  be  found.  A  negative  result  should  never 
be  accepted  as  such  until  a  large  number  of  slides  have  been 
examined.  Neither  should  the  bacillus  be  confused  with  other 
organisms  which  have  a  strong  resemblance  to  it. 

Gram's  method  is  used  for  the  differentiation  of  various 
bacteria,  especially  the  gonococcus.  It  is,  therefore,  very 
frequently  referred  to  as  the  gonococcus  stain.  A  thin  film 
is  prepared,  dried  in  the  air,  and  fixed  in  the  flame.  It  is 
stained  for  a  few  minutes  with  anilin-water  gentian-violet. 
The  result  will  be  better  if  the  stain  is  warmed  slightly. 
Pour  off  the  stain  and  immerse  the  specimen  in  Gram's  solu- 
tion.    It  has  the  following  formula : 


Iodine  crystals, 

1  gram  ; 

Potassium  iodide, 

2  grams; 

Distilled  water. 

300      " 

Stain  until  the  specimen  turns  a  dark  brown.  Wash  in 
95  per  cent,  alcohol  until  color  ceases  to  be  given  off  and  the 
section  is  of  a  grayish  color.  Vesuvin  or  eosin  may  be  used 
as  a  counter- stain.  Wash  in  water,  dry,  and  mount  in  Canada 
balsam.  By  the  action  of  Gram's  solution  on  the  bacteria 
a  compound  is  formed  by  the  bacterial  mycoprotein  and  the 


SPOEES.  87 

iodine  which  is  insoluble  in  alcohol.  Some  bacteria  are 
stained  by  Gramas  method  and  some  are  not.  Those  that  are 
not  stained  are  sometimes  said  to  be  decolorized  by  the  stain. 
Those  that  stain  have  a  purplish  or  blue-brown  color. 

The  following  organisms  do  not  stain  by  Gram's  method : 

Micrococcus  of  gonorrhoea,  or  gonococcus. 

Bacillus  of  typhoid  fever,  or  Bacillus  typhosus. 

Bacillus  coli  communis. 

Spirillum  of  Asiatic  cholera,  or  Comma  bacillus. 

Bacillus  of  influenza. 

Bacillus  of  bubonic  plague. 

Bacillus  Mallei  (glanders). 

Bacillus  of  malignant  oedema. 

Bacillus  of  Friedlaender  (pneumobacillus). 

Sj)irillum  of  relapsing  fever. 

Diplococcus  intracellularis  meningitidis. 

Bacillus  pro  tens  vulgaris. 

Bacillus  pyocyaneus. 
Among  the  bacteria  that  are  stained  are  the : 

Pneumococcus  (Diplococcus  pneumoniae). 

Staphylococcus  pyogenes. 

Streptococcus  pyogenes. 

Bacillus  of  diphtheria. 

Bacillus  tuberculosis. 

Bacillus  of  leprosy. 

Bacillus  anthracis. 

Bacillus  of  tetanus. 

Bacillus  aerogenes  capsulatus. 

Streptothrix  actinomyces. 
Spores  :  Mention  has  been  made  of  the  peculiar  resistance 
exhibited  by  spores  to  extraneous  influences.  It  is  also  very 
difficult  to  stain  them.  The  methods  generally  employed  are 
the  same  as  those  for  staining  the  tubercle  bacillus,  but  the 
film  must  be  exposed  to  the  action  of  the  stain  for  a  longer 
time. 

McFarland  recommends  the  following  method  :  Place  the 
preparation  in  a  test-tube  half  filled  with  a  carbol-fuchsin 
solution  and  boil  it  for  at  least  fifteen  minutes.  Decolorize 
with  3  per  cent,   hydrochloric  or  a  2-5  per  cent,  acetic  acid 


88  MICROSCOPIC  EXAMINATION  OF  BACTERIA. 

solution.  Wash,  counter-stain,  and  mount.  Another  method 
is  first  to  immerse  the  film  for  two  minutes  in  chloroform  and 
then  in  5  per  cent,  chromic  acid  solution  for  1  to  2  minutes. 
When  stained  after  the  method  of  staining  the  tubercle  bacil- 
lus the  result  is  not  very  satisfactory.  The  decolorizing  agent 
should  not  be  so  strong ;  a  3  per  cent,  solution  of  the  acid  is 
sufficient. 

Ajezky  first  places  the  film,  before  fixing,  in  a  hot  0.5  per 
cent,  hydrochloric  acid  solution  for  three  to  four  minutes, 
heating  it  gently.  Decolorize  with  4-5  per  cent,  sulphuric 
acid.  Counter-stain  with  methylene-blue  or  malachite-green 
and  mount. 

Neisser's  method :  Float  the  preparation  on  an  anilin-water 
fuchsin  solution  for  one  hour,  heating  it  constantly  to  near 
the  boiling-point.  Wash  in  water,  decolorize  with  a  25  per 
cent,  solution  of  hydrochloric  acid,  counter- stain,  and 
mount. 

Fiocca's  method :  To  20  c.c.  of  a  10  per  cent,  ammonia  solu- 
tion add  from  10  to  20  drops  of  an  alkaline  solution  of  any 
of  the  anilin  dyes.  Heat  until  steam  is  given  off,  then  place 
the  film  in  the  hot  staining  solution  for  from  5  to  15  minutes. 
Decolorize  in  a  25  per  cent,  solution  of  nitric  or  sulphuric 
acid  ;  wash  in  water,  counter-stain  with  malachite-green,  vesu- 
vin,  or  safranin,  and  mount. 

All  these  methods  stain  the  spore  red,  and  the  parent  germ 
takes  on  the  color  of  the  contrast-stain.  None  of  these 
methods  is  entirely  satisfactory,  and  spore-staining  still  re- 
mains a  discouraging  procedure.  Many  attempts  must  be 
made  before  even  a  measure  of  success  is  attained. 

Capsules  :  When  bacteria  are  grown  artificially  on  culture- 
media,  capsules  usually  do  not  appear.  For  the  demonstration 
of  the  capsules  the  fresh,  germ-containing  material  must  be 
used.  The  sputum  from  a  case  of  lobar  pneumonia  is  most 
suitable. 

Johne's  method :  The  film  is  stained  in  a  warm  2  per  cent, 
solution  of  gentian-violet  for  a  few  minutes  and  decolorized 
in  a  2  per  cent,  solution  of  acetic  acid.  After  washing  in 
water  the  specimen  is  mounted  in  water.  Canada  balsam 
shrinks  the  capsule.     For  permanent  specimens  the  cover- 


FLAG  ELLA.  89 

glass  is  rimmed  with  Tarrant's  cement  or  any  other  good 
cover-glass  cement.^ 

Welch's  method  :  From  a  pipette,  drop  glacial  acetic  acid  on 
the  film,  allowing  it  to  remain  for  a  few  seconds.  Pour  off 
the  acid  (do  not  wash  or  wipe  it  off)  and  stain  with  anilin- 
water  gentian-violet.  Wash  and  restain  until  all  the  glacial 
acetic  acid  has  been  removed.  Then  wash  in  water  containing 
1  or  2  per  cent,  of  sodium  chloride.    Examine  in  salt  solution. 

Flagella  :  It  is  more  difficult  to  stain  flagella  than 
either  the  tubercle  bacillus  or  spores ;  but  it  is  possible  to 
stain  and  demonstrate  them. 

The  method  of  Loeffler  is  the  best.  He  uses  three  solu- 
tions, Nos.  1,  2,  and  3  : 

Solution  Wo.  1. 

20  per  cent,  solution  of  tannic  acid,   10  grams  ; 
Cold  saturated  aqueous  solution  of 

ferrous  sulphate,  5      " 

Aqueous  or   alcoholic    solution    of 

fuchsin  or  methyl-violet,  1  gram. 

Solution  No.  2. 
A  1  per  cent,  solution  of  caustic  soda. 

Solution  No.  S. 

An  aqueous  solution  of  sulphuric  acid  of  such 
strength  that  1  c.c.  will  exactly  neutralize  an 
equal  quantity  of  caustic  soda  solution. 

In  order  to  have  the  flagella  show  well,  the  film  should  be 
spread  as  thinly  as  possible.  Mix  a  small  quantity  of  the 
culture  with  a  drop  of  sterile  water,  and  from  this  mixture 
take  a  small  portion  and  spread  it  on  a  clean  slide  or  cover- 
glass.  Dry  in  the  air  and  fix  in  the  flame.  Cover  the  film 
with  solution  No.  1  (the  mordant)  and  heat  until  it  begins 
to  steam.     Then  wash  in  distilled  water  followed  by  absolute 

*  A  modification  of  Johne's  metliod  is  to  wash  the  film  for  one  minute  in 
a  1  per  cent,  solution  of  acetic  acid  before  the  stain  is  applied. 


90  MICROSCOPIC  EXAMINATION  OF  BACTERIA. 

alcohol  until  the  glass  is  clean.  Dry  and  stain  with  anilin- 
water  fuchsin  having  a  neutral  reaction.  Wash  in  water, 
dry,  and  mount  in  Canada  balsam.  The  stain  is  neutralized 
with  solution  No.  2.  If  the  organism  produces  alkalies, 
solution  No.  3  is  added  in  the  proportion  of  1  drop  to  1  c.c. 
in  16  c.c.  of  the  mordant.  If  the  organism,  on  the  other 
hand,  produces  acids,  solution  No.  2  is  added  in  the  same 
way. 

Loeffler  has  determined  the  exact  quantity  to  be  added  to 
each  16  c.c.  of  mordant  solution  for  staining  the  flagella  of 
the  following : 

Cholera  spirillum,  J—1  drop  of  solution  No.  3. 

Bacillus  typhosus,  1  c.c.  of  solution  No.  2. 

Bacillus  subtilis,  20-30  drops  of  solution  No.  2. 

Bacillus  of  malignant  oedema,  36-37  drops  of  solution 
No.  2. 

Van  Ermengen's  method,  though  complicated,  yields  very 
satisfactory  results.  The  film  is  placed  in  a  fixing  solution 
consisting  of  1  part  of  a  2  per  cent,  solution  of  osmic  acid 
and  2  parts  of  a  10  to  25  per  cent,  solution  of  tannin,  for  one 
hour  at  the  room  temperature.  It  is  then  thoroughly  washed 
in  distilled  water,  and  the  film  transferred  for  a  few  seconds 
to  a  5  per  cent,  solution  of  nitrate  of  silver ;  then  into  the 
following  for  a  few  seconds  : 


Gallic  acid. 
Tannin, 

5  grams ; 
3       " 

Fused  potassium  acetate, 
Distilled  water, 

10       '' 
350  c.c. 

Return  the  film  to  the  silver  solution,  allowing  it  to  remain 
there  until  it  has  turned  black ;  wash  well  in  water,  dry,  and 
mount. 

Pittfield  uses  a  method  which  is  botli  a  mordant  and  a  stain. 
The  solution  is  prepared  as  follows  : 

Saturated  aqueous  solution  of  alum,       10  c.c. ; 
Saturated  alcoholic  solution   of  gen- 
tian-violet, 1    " 
Mix  well  and  filter.     Add  : 


FLAGELLA.  91 

Tannic  acid,  1  gram  ; 

Distilled  water,  10  c.c. 

The  cover  glass  is  spread  with  a  very  thin  film,  dried,  and 
fixed.  Cover  with  the  mixed  solution  and  heat  almost  to 
boiling.  Wash  in  water  until  the  glass  is  clean,  dry,  and 
mount  in  Canada  balsam. 

Muir  has  modified  this  method  by  using  two  solutions,  a 
mordant  and  a  stain  : 

Mordant, 

Tannic   acid   (10   per  cent,   aqueous 

solution,  filtered),  10  c.c. ; 

Corrosive  sublimate  (saturated  aqueous 

solution),  5    " 

Alum  (saturated  aqueous  solution),  5    " 

Carbol-fuchsin,  5    " 

Mix  well,  and  after  the  sediment  has  settled  the  super- 
natant clear  fluid  is  pipetted  into  a  clean  glass-stop- 
pered bottle. 

Stain, 

Alum  (saturated  aqueous  solution),  10  c.c. ; 

Gentian-violet  (saturated  aqueous  solu- 
tion), 2    " 

This  stain  may  be  substituted  for  the  carbol-fuchsin  in  the 
mordant.  Cover  the  film  with  the  mordant  solution  and 
heat  until  steam  arises.  Wash  in  running  water  for  two 
minutes.  Dry  carefully  over  a  flame  and  stain,  heating  as 
before.  Wash  in  water,  dry,  and  mount  in  a  drop  of  xylol 
balsam. 

L.  Smith  stains  the  flagella  with  night-blue.  The  method 
is  simple.  He  advises,  however,  that  only  young  cultures  be 
used.  The  cover-glass  must  be  clean  and  free  from  fatty 
matter.  Mix  1  gram  of  potassium  alum  with  40  c.c.  of  dis- 
tilled water  and  place  in  the  incubator  over  night.  Dissolve 
5  grams  of  night-blue  in  20  c.c.  of  absolute  alcohol  and  mix 
with  the  first  solution.    Filter  until  the  filtrate  comes  through 


92  MICROSCOPIC  EXAMINATION  OF  BACTERIA. 

clear.  Stain  for  five  or  ten  minutes ;  wash  In  water,  dry  in 
the  air,  and  mount  in  Canada  balsam. 

Staining  bacteria  in  tissue  :  The  tissue  is  removed, 
fixed,  and  hardened  according  to  the  rules  laid  down  in  text- 
books on  histology,  and  embedded  in  celloidin  or  paraffin. 
The  cut  sections  are  stained  with  Loeffler's  alkaline  methy- 
lene-blue,  and  then  differentiated  with  a  1  per  cent,  solution 
of  hydrochloric  acid  for  a  few  seconds,  dehydrated  in  absolute 
alcohol,  cleared  in  xylol,  and  mounted  in  balsam. 

Pfeiffer  stains  the  sections  for  one-half  hour  in  dilute 
carbol-fuchsin,  and  then  transfers  them  to  absolute  alcohol 
slightly  acidulated  with  acetic  acid.  As  soon  as  the  section 
takes  on  a  reddish-violet  color  it  is  transferred  to  xylol, 
cleared,  and  mounted  in  balsam. 

A  very  simple  method  is  to  stain  with  the  ordinary  aqueous 
staining  solutions  for  from  five  to  eight  minutes,  and  then 
decolorize  in  a  1  per  cent,  acetic  acid  solution  for  a  few 
seconds.  This  removes  the  stain  from  the  tissues,  but  leaves 
the  color  in  the  bacteria.  Any  contrast-stain  may  be  used, 
after  which  the  specimen  is  dehydrated  in  absolute  alcohol, 
cleared  in  xylol,  and  mounted.  Gram\s  stain  is  used  also 
for  staining  bacteria  in  tissue.  The  specimen  is  stained  first 
in  Ehrlich^s  anilin-water  gentian-violet  for  from  five  to  thirty 
minutes,  washed  in  water,  immersed  in  Gram's  solution  for  a 
few  minutes,  washed  in  95  per  cent,  alcohol  until  thoroughly 
decolorized,  dehydrated  in  absolute  alcohol,  cleared  in  xylol, 
and  mounted. 


CHAPTER    X. 

EXPERIMENTS  UPON  ANIMALS. 

The  inoculation  of  animals  with  the  germs  of  various  infec- 
tious diseases  has  been  the  means  of  enabling  us  to  observe 
accurately  and  to  record  the  progressive  growth  and  develop- 
ment of  pathogenic  bacteria  in  the  living  body  and  the  con- 
ditions resulting  therefrom.  Animal  experimentation  has 
been  of  inestimable  value  in  medicine,  especially  in  physi- 
ology, materia  medica,  therapeutics,  and  bacteriology.  In 
bacteriology  it  is  an  aid  in  the  diiferentiation  and  detection  of 
bacteria  as  well  as  in  the  determination  of  their  pathogenicity. 

White  mice,  guinea-])igs,  rabbits,  and  monkeys  are  the 
animals  usually  used  for  this  purpose.  They  are  of  a  size 
that  will  not  interfere  with  the  work  ;  they  can  be  kept  in 
the  laboratory ;  and  they  are  also  very  susceptible  to  the 
various  infectious  diseases. 

We  must,  however,  remember  that  some  animals  possess  a 
natural  immunity  or  resistance  to  certain  diseases,  and  cannot 
be  used  for  work  connected  with  such  diseases. 

The  animals  should  be  kept  in  a  clean  wire  cage  in  a  light, 
well- ventilated  room.  They  should  have  plenty  of  good  food 
and  fresh  water,  and  every  care  taken  of  them.  The  experi- 
ments should  be  performed  with  the  same  care  as  an  opera- 
tion— for  such  the  experiments  really  are — on  the  human 
being.  Careless  and  negligent  handling  of  these  animals  is 
not  only  unpardonable,  but  also  unnecessary. 

The  inoculations  may  be  made  directly  into  a  vein  (intra- 
venous injection) ;  into  the  subcutaneous  tissues  ;  or  into  the 
peritoneal  cavity. 

It  is  preferable  to  use  a  syringe  that  can  be  sterilized 
easily.  Koch's  syringe  is  used  more  than  any  other.  It  con- 
tains no  piston,  the  contents  being  forced  out  with  a  rubber 
bulb ;  and  when  this  bulb  is  removed,  it  can  be  sterilized  by 

93 


94  EXPERIMENTS   UPON  ANIMALS. 

dry  heat.  The  objection  to  most  syringes  used  for  this  pur- 
pose is  that  the  packing  is  made  of  rubber  or  leather,  and 
cannot  be  sterilized  by  heat  of  any  kind.  The  syringes  and 
all  other  apparatus  used  in  the  performance  of  these  animal 
experiments  should  be  sterilized  thoroughly  both  before  and 
after  using. 

Inoculations  are  made  also  with  the  platinum  needle,  which 
is  passed  in  through  a  small  opening  made  in  the  skin. 

No  matter  where  nor  how  the  inoculation  is  to  be  made, 
the  first  steps  are  to  remove  all  hair  from  the  site  of  inocu- 
lation with  scissors  and  a  razor;  and  then  to  disinfect  the 
skin  in  order  to  avoid  any  possible  contamination  or  in- 
fection with  pus  cocci.  Some  bacteriologists  advise  snipping 
off  a  small  piece  of  skin  with  curved  scissors,  of  a  size  suf- 
ficient not  to  draw  blood,  but  to  remove  the  surface  epithelium, 
thus  leaving  a  denuded  spot  through  which  the  needle  can  be 
introduced.  This  absolutely  precludes  the  possibility  of  con- 
taminating the  injection. 

Fluids  in  large  quantities  are  injected  into  the  circulation 
or  into  the  peritoneal  cavity  by  forcing  them  through  a 
slender  canula  with  a  syringe  or  rubber  bulb. 

When  injections  are  made  into  the  peritoneal  cavity,  care 
must  be  taken  not  to  injure  any  of  the  abdominal  organs. 
The  intestines  usually  slip  out  of  the  way  of  the  advancing 
needle  or  canula,  and  are  not  so  apt  to  be  injured  as  the  liver 
or  stomach.  The  injection  is  made  in  the  same  manner  as 
is  any  hypodermic  injection  and  under  the  same  antiseptic 
precautions. 

Intravenous  inoculation  is  done  usually  on  rabbits  because 
the  ear  vein  of  the  rabbit  is  conspicuous  and  within  easy 
reach.  Small  animals  are  unsuited  for  this  form  of  inocula- 
tion. After  thoroughly  cleansing  the  ear  the  veins  are  dis- 
tended momentarily  by  compressing  them  at  the  base  of  the 
ear.  The  needle  is  introduced  at  the  root  of  the  ear,  point- 
ing in  the  direction  of  the  current  of  blood,  and  the  injection 
made  slowly.     The  puncture  is  sealed  with  collodion. 

For  subcutaneous  injections,  mice  are  used.  The  inocula- 
tion is  made  at  the  root  of  the  tail,  where  a  little  pocket  is 
made  for  the  reception  of  the  material. 


SPECIAL   CONSIDERATIONS.  95 

If  it  is  desired  to  make  an  inoculation  directly  into  the 
lymphaticSj  some  organ  with  a  very  poor  blood-supply  should 
be  chosen.  The  choice  is  the  testicle,  the  injection  being 
made  deeply  into  the  organ. 

Pasteur  inoculated  rabbits  with  hydrophobia  virus  by  in- 
jecting an  emulsion  of  the  spinal  cord  of  an  animal  sick  with 
hydrophobia  ^engg^A  the  dura  ma^erth  rough  a  trephine-open- 
ing  made  a  sTioirFdistance  back  of  the  eyes. 

For  the  purpose  of  studying  the  local  effects  of  various 
bacteria,  inoculations  are  made  into  the  anterior  chamber  of 
the  eye.  An  incision  is  made  through  the  cornea  with  a 
cataract  knife  and  a  liquid  culture  injected,  or  solid  material 
is  introduced  with  the  platinum  needle  or  forceps. 

Special  considerations :  Injections  may  be  made  without  the 
use  of  an  ancesthetic.     Painful    operations  are  made  under 

Fig.  34. 


Mouse-holdur,  with  mouse  in  proper  position. 

ether  anaesthesia.  Chloroform  is  apparently  not  well  borne 
by  animals.  When  the  inoculation  is  to  be  made,  the  animal 
is  wrapped  securely  in  towels,  leaving  the  site  of  inoculation 
exposed.  An  assistant  holds  the  animal  and  keeps  it  from 
struggling.  Special  holders  (Figs.  34,  35,  36)  have  been  de- 
vised for  the  smaller  animals.  They  are  simple  in  construc- 
tion, convenient,  and  inexpensive. 

Young  animals  are  preferable  to  old  ones.  Intravenous 
injections  are  the  most  fatal,  and  only  a  small  dose  of  the 
culture  or  suspected  material  should  be  injected.  Peritoneal 
injection  produces  results  more  rapidly  than  subcutaneous 
injection.     Virulent  cultures  should  always  be  used.     They 


96 


EXPERIMENTS   UPON  ANIMALS, 
Fig.  35. 


Kitasato's  mouse-holder. 


are  grown  on  such  media  as  have  a  tendency  to  increase  their 
virulence.  The  amount  of  material  introduced  should  be  in 
proportion  to  the  size  of  the  animal. 


Fig.  36. 


Holder  for  larger  animals. 


After  inoculation  the  animal  should  be  watched  constantly 
and  a  note  made  of  any  change  in  its  condition.  The  tem- 
perature is  taken  at  regular  intervals  per  rectum,  with  a  spe- 


autopsy:  97 

cial  rectal  thermometer  kept  for  that  purpose.  The  normal 
temperature-standard  of  the  animal  should  be  ascertained 
before  the  experiment  is  begun.  The  animal  should  receive 
the  same  care  as  is  given  to  a  patient  after  operation.  Blood 
for  experimental  purposes  is  taken  from  any  vein  ;  or  from  the 
carotid  artery  of  the  smaller  animals. 

The  animal  itself  may  be  used  as  culture-medium  and  incu- 
bator combined.  A  collodion  capsule  containing  the  inoculated 
bouillon  is  suspended  in  the  peritoneal  cavity  of  the  animal. 
The  body-juices  pass  through  the  walls  of  this  capsule,  sup- 
plying the  culture  with  ideal  nourishment,  and  the  germs  are 
not  subject  to  destruction  by  phagocytosis.  The  animal 
remains  free  from  infection.  Such  cultures  grow  rapidly  and 
luxuriantly. 

Autopsy:  Many  important  data  can  be  collected  from 
autopsies  held  on  animals  that  succumb  to  inoculation.  The 
animal  is  washed  thoroughly  with  a  1  :  1000  bichloride  solu- 
tion and  laid  on  its  back  on  a  small  autopsy  board.  In  the 
sides  of  this  board  are  a  number  of  small  nails,  to  which  the 
legs  of  the  animal  can  be  tied.  The  scalpel  is  held  in  the  flame 
for  a  few  minutes,  and  the  thorax  and  abdomen  are  opened 
after  the  surface  of  the  skin  has  been  seared  with  the  heated 
knife.  Every  precaution  should  be  taken  to  avoid  infection 
and  contamination.  Bouillon  cultures  are  made  from  the 
body-juices  and  from  the  internal  organs.  The  surface  is 
seared,  incised  with  a  sterile  knife,  and  a  particle  of  the  organ 
removed  with  the  platinum  loop. 

When  the  animal  is  killed  for  the  purpose  of  studying  the 
results  of  the  infection,  smear-preparations  are  made  of  the 
hearths  blood  or  blood  obtained  from  any  vessel.  Pieces  of  tis- 
sue of  suitable  size  are  fixed  and  hardened  in  95  per  cent,  alcohol. 

At  the  completion  of  the  autopsy  both  the  animal  and  the 
board  are  placed  in  a  1  :  1000  bichloride  solution  for  one  hour 
and  then  destroyed  by  burning.  All  the  instruments,  etc., 
used  in  the  conduction  of  the  autopsy  are  sterilized  by  live 
steam.  Tlie  bacteriologist  should  take  every  precaution  to 
protect  himself  from  infection.  All  wounds  of  any  kind  on 
the  hands  should  be  protected  with  collodion ;  or  rubber 
gloves  worn. 

7— Bact. 


CHAPTEE    XI. 

POISONOUS  PRODUCTS  OF  BACTERIA. 

.  Alt.  the  symptoms  manifested  as  a  result  of  the  presence 
of  bacteria  in  the  body  are  due  to  the  elaboration  by  these 
bacteria  of  substances,  the  chemical  composition  of  which 
resembles  that  of  the  vegetable  alkaloids.  Some  of  these 
substances  are  formed  by  bacteria  outside  of  the  body  and  are 
ingested  with  food,  as  poisoning  by  decomposed  meat,  fish, 
cheese,  or  ice  cream.  In  most  cases,  however,  the  poison  is 
elaborated  by  the  bacteria  after  they  have  gained  entrance 
into  the  body,  as  in  the  infectious  fevers.  The  severity  of  the 
reaction  depends  upon  the  kind  and  the  quantity  of  poison 
elaborated. 

Ptomaines :  A  ptomaine  is  an  organic  chemical  compound, 
basic  in  character,  formed  by  the  action  of  bacteria  on  nitro- 
genous matter  (Vaughan  and  Novy).  A  ptomaine  is  crys- 
tal lizable.  It  may  be  either  inert  or  very  poisonous.  Brieger 
calls  the  non-poisonous  substances  ptomaines,  and  the  poison- 
ous ones,  toxins.  When  a  ptomaine  is  injected  into  an 
animal  in  large  quantity  or  for  a  long  period  of  time,  symp- 
toms of  intoxication  are  produced.  Some  ptomaines  contain 
oxygen  and  some  do  not.  They  all  contain  nitrogen. 
Ptomaines  are  typical  vegetable  alkaloids. 

Ptomaines  have  also  been  called  cadaveric  alkaloids,  because 
they  are  the  result  of  putrefaction.  The  kind  of  ptomaine 
produced  depends  largely  on  the  individual  germ,  the  tem- 
perature, amount  of  oxygen  present,  virulence  or  activity  of 
the  germ,  and  the  quality  of  the  nutritive  medium.  Ptomaines 
are  regarded  as  cleavage-products,  temporary  forms  of  matter, 
as  they  are  changed  from  an  organic  to  an  inorganic  state  by 
the  action  of  the  bacteria.  Although  ptomaines  may  be 
formed  by  pathogenic  bacteria,  they  are  usually  the  result  of 
the  activity  of  the  non-pathogenic  saprophytes. 


LEUCOMAINES— TOXINS.  99 

Leucomaines :  A  leucoraaine  is  an  animal  alkaloid,  a  basic 
substance,  resulting  from  the  tissue  metabolism  of  the  normal 
body.  Tliey  are  derived  principally  from  the  nucleins  of 
the  nuclei  and  the  proteids  of  the  cell-protoplasm.  Accord- 
ing to  some,  they  play  a  very  important  role  in  the  antitoxin 
theories.  AH  the  various  poisonous  substances,  elaborated 
and  excreted  in  the  urine  and  saliva,  etc.,  as  well  as  the 
venoms  of  certain  snakes,  etc.,  belong  to  this  group.  At  one 
time  they  were  regarded  as  being  due  to  bacterial  activity. 

Toxalbumin :  A  toxalbumin  is  a  non-basic  bacterial  substance 
partaking  of  the  chemical  composition  of  an  albumin.  Tox- 
albumins  are  not  volatile  and  are  extremely  poisonous.  The 
poisons  produced  by  the  typhoid  bacillus,  spirillum  of  cholera. 
Staphylococcus  pyogenes,  bacillus  of  diphtheria,  and  the 
tetanus  bacillus,  belong  to  this  group.  Many  bacteriologists 
have  abandoned  this  term  entirely  because  of  the  as  yet  unde- 
termined nature  of  these  substances.  They  usually  are  con- 
sidered together  with  the  toxins.  Ricin  and  abrin,  which  are 
obtained  from  the  castor  oil  bean  and  the  jequirity  bean, 
respectively,  are  toxalbumins  of  vegetable  origin.  They  are 
extremely  sensitive  to  the  action  of  light,  heat,  and  chemicals. 

Toxins :  A  toxin  is  a  synthetic  product  elaborated  by 
bacteria  when  growing  in  nutrient  media  or  in  the  body.  It 
is  not  crystallizable.  It  is  extremely  poisonous,  even  in 
minute  doses.  The  chemistry  of  the  toxins  is  not  definitely 
known,  as  it  has  so  far  been  impossible  to  isolate  a  toxin 
chemically  because  of  its  instability.  It  has  been  suggested 
that  the  toxins  are  closely  allied  to  the  ferments,  because 
when  injected  into  an  animal  considerable  time  elapses  before 
death  occurs.  Further,  because  only  a  very  small  quantity  is 
sufficient  to  cause  death.  Snake-venom,  abrin,  and  ricin 
resemble  the  bacterial  toxins  in  their  action. 

Toxins  are  of  two  kinds :  First,  those  which  are  probably 
bacterial  excretions.  Second,  those  which  are  present  only  in 
the  body  of  the  germ.  The  first  named  are  obtained  by  fil- 
tration from  an  actively  growing  bouillon  culture.  The 
toxins  of  different  germs  differ  very  greatly  in  their  poison- 
ous qualities.  For  instance,  the  poison  of  the  tetanus  bacillus 
is  extremely  virile.     A  mouse  weighing   15  grams  can    be 


100  POISONOUS  PRODUCTS  OF  BACTERIA. 

killed  by  the  almost  inconceivable  amount  of  0.00000005  of 
a  gram  of  the  toxin.  The  toxins  of  other  organisms  are  not 
nearly  so  poisonous.  The  severe  constitutional  symptoms 
accompanying  typhoid,  diphtheria,  tetanus,  pneumonia,  etc., 
are  sufficient  evidence  to  prove  that  the  germs  causing  these 
diseases  have  not  merely  a  local  action,  but  that  they  also 
elaborate  some  substance  which  is  absorbed  and  disseminated 
throughout  the  body,  and  to  which  the  general  reaction  is 
due.  These  substances  are  certainly  poisonous,  or  toxic,  and 
therefore  are  referred  to  as  toxins.  The  intensity  (jf  the  gen- 
eral reaction  would  depend  naturally  on  the  amount  of  toxin 
absorbed  and  its  intensity. 

That  the  body  of  the  germ  also  contains  a  toxin  can  be 
demonstrated  by  the  injection  of  dead  cultures,  which  is  fol- 
lowed by  a  typical  reaction. 

Buchner  calls  all  these  toxins  bacterial  proteins.  Those 
which  cause  fever  he  terms  pyogenic ;  those  which  cause 
inflammation,  phlogogenic.  Koch's  old  tuberculin  and  mal- 
lein  are  proteins. 


CHAPTER  XII. 

INFECTION. 

By  infection  we  understand  the  entrance  of  bacteria  into 
the  body  and  their  multiplication  there.  Theoretically  that 
definition  is  correct ;  but  something  more  than  the  entrance 
and  multiplication  of  bacteria  is  necessary  to  constitute  an  in- 
fection. Their  presence  and  multiplication  must  be  mani- 
fested by  symptoms.  A  person  may  swallow  the  typhoid 
bacillus  without  contracting  the  disease.  Theoretically  that 
constitutes  an  infection,  but  that  is  not  the  case  practically, 
because  the  germ  does  not  manifest  its  presence  by  any  dis- 
turbance of  the  health  of  the  individual. 

Some  injury  must  be  done  the  body  by  the  germ  before 
there  can  be  said  to  be  an  infection.  The  surface  of  the  skin 
is  known  to  harbor  bacteria  at  all  times,  but  unless  searched 
for  they  remain  unrecognized.  They  multiply  there,  and  yet 
there  is  no  evidence  of  infection.  When  these  same  germs 
enter  a  wound  and  produce  substances  which  react  on  the  body, 
an  infection  is  said  to  have  occurred.  It  is  impossible  to  give 
a  definition  of  infection  that  can  be  embraced  in  one  sentence. 

Infection  may  occur  not  only  with  the  vegetable  organisms 
{i.  e.,  bacteria,  moulds,  and  yeasts),  but  also  with  the  animal 
parasites,  such  as  the  Amoeba  coli  and  the  malarial  hematozoon. 

An  infectious  disease  is  one  caused  by  micro-organisms,  and 
which  is  liable  to  be  communicated  to  others.  The  non- 
pathogenic bacteria  are  incapable  of  producing  an  infectious 
disease.  Some  organisms  are  infectious  for  animals  but  not 
for  man,  and  vice  versa.  In  the  condition  known  as  saprcemia 
the  infection  is  due  to  saprophytes  which,  while  not  entering 
the  blood  themselves  (/.  e.,  remaining  in  the  focus  of  infec- 
tion), yet  produce  substances  that  are  absorbed  by  the  body 
and  enter  into  the  blood  and  lymph-channels. 

By  mixed  infection  is  meant  the  presence  of  more  than  one 

101 


102  INFECTION. 

organism  at  the  same  time.  This  is  seen  frequently  in  tuber- 
culosis, pneumonia,  wound  infections,  etc.  A  secondary  in- 
fection is  one  occurring  in  the  course  of  another  infection, 
such  as  the  streptococcus  infections  which  occur  in  the  course 
of  pulmonary  tuberculosis.  A  terminal  infection  is  one  occur- 
ring in  an  individual  suffering  from  some  chronic  organic  dis- 
ease and  which  ends  fatally. 

When  the  poison  is  generated  within  the  body  itself  as  the 
result  of  faulty  metabolism  or  inadequate  elimination  of  waste 
products  and  their  subsequent  decomposition,  a  form  of  poison- 
ing occurs  known  as  autointoxication,  or  autoiiifection.  This 
form  of  poisoning  should  not  be  confused  with  poisoning  by 
alcohol,  which  also  is  defined  as  an  intoxication. 

An. infectious  disease  is  said  to  be  contagious  when  the  in- 
fection is  conveyed  by  fomites,  as,  for  instance,  the  scales  in 
scarlet  fever.  All  contagious  diseases  are  infectious  diseases 
as  well ;  but  all  infectious  diseases  are  not  contagious. 
Typhoid  fever  is  a  typical  infectious  disease.  The  two  terms 
are  really  synonymous,  and  yet  there  is  a  difference  in  the 
method  of  conveyance  of  the  disease. 

In  an  infectious  disease  the  germ  is  the  infecting  medium, 
and  is  carried  from  the  sick  to  the  well;  whereas  in  a  con- 
tagious disease  some  medium,  such  as  the  scales  in  the  exan- 
thematous  diseases,  apparently  carries  the  infection.  A  more 
thorough  study  of  the  contagious  diseases  and  the  finding  of 
the  exciting  germ-cause  may  obviate  the  necessity  of  a  divis- 
ion into  infectious  and  contagious  diseases. 

The  term  miasmatic  had  reference  to  a  disease  due  to  a 
"  miasm,'' — that  is,  noxious  matter  carried  in  the  air.  Malaria 
was  looked  upon  as  the  type  of  this  class.  The  term  is  no 
longer  used  since  the  method  of  infection  has  been  deter- 
mined. 

Although  certain  germs  bear  a  causal  relationship  to  dis- 
ease, it  is  evident  that  the  development  of  the  disease,  or  the 
manifestation  of  an  infection,  is  dependent  on  many  condi- 
tions which  influence  the  infection  either  one  way  or  the  other. 
All  the  conditions  favorable  to  the  development  and  growth 
of  an  organism  must  exist  before  disease  will  result.  A 
whole  community  may  be  exposed  to  the  infection  in  its  most 


INFECTION.  103 

virulent  form  and  yet  escape  the  disease.  On  the  other  hand, 
certain  individuals  will  succumb  rapidly  even  when  the  infec- 
tive agent  is  attenuated.  Again,  the  severity  of  the  disease 
depends  not  only  on  the  individual  susceptibility,  but  also 
upon  the  vitality  of  the  germ,  the  source  of  the  infection,  and 
the  time  and  point  of  entrance  of  the  infective  agent. 

The  accidental  presence  of  a  germ  in  the  body  of  an  indi- 
vidual during  disease  cannot  be  accepted  as  evidence  of  its 
etiologic  relationship  with  that  particular  disease.  Koch  has 
laid  down  some  requirements,  known  as  Koch's  law,  with 
which  the  organism  must  comply  before  it  can  be  considered 
as  the  specific  cause  of  a  disease : 

1.  That  the  organism   should  always  be  present  in  the 

body  of  the  animal  having  the  disease,  and  that 
its  presence  must  explain  the  changes  met  with  in 
that  disease. 

2.  That  it  must  be  possible  to  isolate  and  make  a  pure 

culture  of  the  organism  outside  of  the  body. 

3.  That  the  inoculation  of  an  animal  with  a  pure  culture 

of  this  organism  will  result  in  the  production  of  the 
typical  disease  from  which  the  germ  was  obtained. 

4.  That  the  typical  organism  be  found  in  the  tissues  of 

the  animal  thus  inoculated. 

A  number  of  organisms  have  been  accepted  as  specific  that 
do  not  meet  all  of  these  requirements,  but  the  evidence  in 
their  favor  is  so  overwhelming  that  the  specificity  cannot  be 
doubted.  The  tubercle  bacillus  is  an  example.  It  has  not, 
according  to  many  observers,  as  yet  met  the  last  two  require- 
ments in  man. 

Bacteria  are  phlogistic,  producing  simply  a  local  inflamma- 
tory reaction  (staphylococcus) ;  toxic,  a  local  growth  (/.  e., 
without  invading  the  body  themselves),  w^ith  rapid  and  exten- 
sive dissemination  of  the  toxin  (tetanus  and  diphtheria) ; 
septic,  invading  (themselves)  the  body-fluids  (anthrax). 

A  disease  is  said  to  be  sporadic  when  only  isolated  cases 
appear  ;  endemic,  when  the  disease  is  always  present ;  epidemic, 
when  it  is  unusually  prevalent  and  exhibiting  a  marked  ten- 
dency to  spread  beyond  its  usual  limitations ;  pandemic,  when 
the  disease  is  widely  spread,  as  in  several  states  or  countries. 


104  INFECTION. 

Conditions  Modifying  Infection. 

The  germ  :  Virulence :  Much  depends  upon  the  activity 
of  the  germ  at  the  time  of  infection.  Its  activity  is  known 
as  its  virulence.  This  virulence  is  extremely  variable  and 
subject  to  many  influences.  Not  only  is  there  a  difference  in 
the  virulence  of  various  pathogenic  organisms,  but  the  viru- 
lence of  any  one  germ  is  also  subject  to  variations. 

All  pathogenic  bacteria  have  a  toxin-forming  and  a  vege- 
tative function.  When  the  vegetative  function  especially  is 
marked,  the  toxin-forming  function  is  diminished,  and  vice 
versa.  It  is  apparently  impossible  for  both  functions  to  be 
present  in  the  same  proportions  at  the  same  time.  This  varia- 
tion is  dependent  on  the  biologic  characteristics.  In  one 
instance  the  organism  will  grow  very  luxuriantly  with  the 
production  of  little  toxin.  All  its  energy  is  spent  in  the 
direction  of  growth  and  propagation.  At  other  times  it 
grows  very  poorly,  but  produces  enormous  quantities  of  toxin 
or  small  quantities  of  an  extremely  powerful  toxin.  The 
toxin-forming  function  is  carried  on  at  the  expense  of  the 
reproductive  function. 

In  the  laboratory  the  virulence  is  attenuated  by  repeated 
transplantation  on  artificial  media.  Those  conditions  which 
are  conducive  to  growth  and  multiplication  are  supplied,  and 
by  artificial  selection  the  vegetative  function  becomes  the  pre- 
dominating one.  If  this  vegetative  organism  is  then  rapidly 
passed  from  one  animal  to  another,  conditions  are  created 
which  favor  the  development  of  the  toxin-forming  function, 
with  the  result  that  the  organism  multiplies  more  slowly,  but 
elaborates  enormous  quantities  of  toxin  or  small  quantities  of 
a  very  powerful  toxin. 

The  virulence  may  be  increased  by  growing  the  bacterium 
in  a  collodion  sac  placed  in  the  peritoneal  cavity  of  an  animal, 
so  that  it  may  become  accustomed  to  the  body-fluids. 

By  associating  certain  organisms  the  virulence  may  either 
be  increased  or  diminished.  The  association  of  the  Strepto- 
coccus pyogenes  with  the  bacillus  of  diphtheria  increases  the 
virulence  of  the  latter  considerably.  Frequently  this  is  seen 
clinically  in   cases  of  diphtheria   in  which   there  is  a  mixed 


CONDITIONS  MODIFYING  INFECTION  105 

infection  with  the  streptococcus.  The  virulence  of  the  bacil- 
lus of  malignant  oedema  is  increased  when  it  is  associated 
with  the  Bacillus  prodigiosuSy  a  non-pathogenic  organism. 
Typhoid  cultures  are  increased  in  virulence  when  associated 
with  dead  cultures  of  the  Bacillus  coli  communis. 

These  mixed  infections  play  a  very  important  role  clini- 
cally, as  the  course  of  the  disease  is  influenced  considerably 
thereby.  A  mixed  infection  which  contains  the  streptococcus 
is  a  very  intractable  process,  and  much  more  serious  than  a 
simple  infection.  Occasionally  one  organism  will  inhibit  the 
growth  of  another,  and  thus  diminish  its  virulence.  A  mixed 
infection  may  convert  a  local  into  a  general  infection.  Epi- 
demics are  in  a  measure  due  to  increased  virulence  of  the 
germ.  The  virulence  is  exalted  by  the  rapid  passage  of  the 
organism  from  one  individual  to  another. 

Number :  A  small  number  of  virulent  germs  may  pro- 
duce disease  as  rapidly  as  a  large  number  w-ould  ;  whereas  a 
large  number  is  necessary  if  the  germs  are  attenuated. 
Infection  with  a  small  number  of  any  organism  poss^sed  of 
little  virulence  usually  does  not  result  in  disease.  A  number 
that  would  be  pathogenic  for  a  mouse  would  not  be  patho- 
genic for  an  elephant.  With  these  modifications,  the  number 
of  the  invading  bacteria  is  of  importance,  otherwise  not. 

Avenue  of  infection  :  Bacteria,  in  order  to  produce 
their  characteristic  results  after  invasion  of  the  body,  must 
have  entered  the  body  through  the  proper  channel:  The 
avenue  of  entrance  will  modify  the  infection.  The  typhoid 
bacillus  when  injected  into  the  subcutaneous  tissues  does 
not  produce  typhoid  fever,  but  simply  a  local  abscess.  When 
the  tubercle  bacillus  enters  through  the  respiratory  or  intes- 
tinal tract,  it  produces  typical  tuberculosis ;  but  when  infec- 
tion occurs  through  the  skin,  a  local  tuberculosis  results 
(lupus),  which  runs  an  extremely  slow  course  and  does 
not  tend  to  end  fatally.  The  streptococcus  injected  sub- 
cutaneously  produces  erysipelas  or  extensive  suppuration. 
W^hen  injected  directly  into  the  blood-current  or  lymph- 
channels,  it  produces  septicaemia  or  ^'  blood-poisoning  '\  Inha- 
lation of  the  pneumococcus  is  followed  by  lobar  pneumonia ; 
when  it  enters  by  any  other  route,  it  causes  suppuration  and 


106  INFECTION. 

abscess-formation.     The  same  is  true  of  every  other  patho- 
genic organism. 

The  individual  :  The  susceptibility  of  the  individual, 
or  his  resistance  to  disease,  materially  modifies  the  occurrence 
of  infection.     These  conditions  are  dependent  upon  : 

a.  Immunity :  An  individual  may  possess  a  natural  or  ac- 
quired resistance  to  a  certain  disease,  thus  making  the  occur- 
rence of  infection  with  the  organism  causing  that  disease  impos- 
sible or,  at  least,  difficult.  The  condition  of  immunity  is  not 
absolute,  as  extremely  virulent  organisms  will  produce  dis- 
ease even  in  an  immune.  Usually,  however,  the  disease  then 
occurs  in  a  very  modified  form  (see  also  Chapter  XIIL). 

b.  Vital  condition:  A  healthy  and  vigorous  person  will 
naturally  resist  invasion  much  better  than  one  suffering  from 
some  disease,  such  as  cancer,  diabetes,  or  a  heart-,  kidney-,  or 
liver-disease.  Young  individuals  are  more  susceptible  to 
some  diseases  than  older  persons,  and  old  people  are  attacked 
by  infectious  disease  which  the  younger  individual  escapes. 
Women  are  more  predisposed  to  some  infections  than  men, 
and  some  infections  are  seen  much  more  frequently  in  men 
than  in  women.  Environment  is  largely  responsible  for  this. 
Women,  being  more  confined  to  the  house,  naturally  are 
exposed  to  diseases  which  are  the  result  of  such  confinement. 
The  lack  of  fresh  air  and  exercise  influences  the  vitality  and 
resistance  of  the  woman.  Diseases  incident  to  exposure, 
such  as  pneumonia,  occur  more  often  in  men.  Anything  that 
has  a  tendency  to  diminish  bodily  resistance  in  any  way  pre- 
disposes to  infection. 

c.  Traumatism :  This  usually  predisposes  to  infection  by 
creating  conditions  favorable  to  the  development  of  bacteria. 
The  natural  resistance  of  the  uninjured  tissue  to  infection  is 
diminished  by  the  traumatism,  and  also  the  shock  incident 
thereto.  The  unbroken  skin  never  serves  as  an  infection 
atrium,  whereas  infection  is  invited  by  an  injury.  These  inju- 
ries include  operations.  Tuberculosis  of  the  bones  and 
joints  often  follows  an  injury  of  some  kind  even  when  the 
skin  is  not  broken.  Malignant,  ulcerative  endocarditis  never 
results  unless  there  has  been  some  previous  injury  of  the 
heart  valves.     This  has  been  demonstrated  both  clinically 


CONDITIONS  MODIFYING  INFECTION.  107 

and  experimentally.     It  is  evident,  then,  that  as  soon  as  the 
natural  resistance  of  the  body  is  lessened  infection  is  invited. 

d.  Predisposition :  In  some  instances  there  exists  a  predis- 
position to  certain  diseases.  Certain  races  and  peoples  have 
an  inborn  susceptibility  or  resistance  to  some  of  the  infec- 
tious diseases.  For  instance,  the  colored  races  are  immune 
to  yellow  fever  but  very  susceptible  to  smallpox.  The  fair- 
skinned  races,  on  the  other  hand,  are  extremely  susceptible 
to  yellow  fever. 

e.  Heredity:  It  is  believed  by  some  that  certain  infectious 
diseases  (tuberculosis,  syphilis)  may  be  inherited  by  the  off- 
spring, from  the  father  or  mother,  or  from  both.  Consider- 
able evidence  has  been  offered  in  support  of  this  supposition, 
but  when  this  evidence  is  weighed  carefully  it  falls  far  short 
of  being  conclusive.  For  the  present  such  a  theory  is  unten- 
able. The  (^hild  born  of  weak  or  sickly  parents  cannot  possess 
sufficient  vitality  to  combat  disease,  and  naturally  will  suc- 
cumb to  infection  more  readily  than  a  child  born  of  healthy 
parents.  With  regard  to  syphilis,  there  is  considerable  evi- 
dence at  hand  in  support  of  the  belief  that  it  is  possible  to 
inherit  the  disease  or  to  be  born  with  active  manifestations 
of  the  disease.  Space  forbids  a  more  detailed  consideration 
of  this  very  interesting  subject,  and  we  must  refer  our  readers 
to  the  numerous  dissertations  on  the  subject  which  can  be 
found  in  the  current  literature. 

Sources  of  infection  :  As  has  been  pointed  out,  the  sur- 
face of  the  body,  the  various  mucous  membranes,  and  all  the 
tracts  which  open  on  the  surface  of  the  body,  harbor  an 
extensive  and  varied  flora  at  all  times.  Nuttall  has  shown 
that  the  newly  born  animal  is  absolutely  free  from  bacteria, 
but  that  before  long  it  is  the  host  of  a  large  number  of  patho- 
genic and  non-pathogenic  bacteria.  Different  parts  of  the 
body  harbor  germs  which  produce  diseases  peculiar  to  that  part, 
and  tlius  the  individual  may  be  the  source  of  his  own  infection. 

Skin  :  On  the  skin  we  always  find  various  species  of  staphy- 
lococci, especially  the  Staphylococcus  epidermidis  alhus.  The 
Bacillus  graveolens  is  responsible  for  the  odor  of  sweating 
feet ;  the  Bacillus  prodigiosus,  of  red  sweat ;  but  neither  of 
these   germs  is   pathogenic.     It    is   very   improbable,   how- 


108  INFECTION. 

ever,  that  infection  can  take  place  through  the  unbroken  skin, 
but  the  most  minute  wound  or  abrasion  may  serve  as  an  in- 
fection atrium.  The  bites  of  insects  may  furnish  botli  the 
wound  and  the  infective  material.  Sometimes  the  infection 
atrium  is  so  insignificant  as  to  be  almost  if  not  quite  invisible. 

Conjunctivae:  The  conjunctival  mucous  membrane  is  always 
moist  and  offers  a  most  convenient  lodging-place  for  bacteria. 
McFarland  found  a  very  large  variety  of  bacteria  on  this 
membrane,  but  no  fixed  species.  Others  claim  that  it  is  abso- 
lutely sterile,  because  it  is  bathed  continually  in  a  secretion 
which  possesses  natural  germicidal  powers.  Congestion  or 
hypersemia  increases  the  number  of  leucocytes,  clogging  the 
tissues  and  interfering  with  their  nutrition.  Death  of  tissue 
(necrosis)  follows,  and  every  barrier  to  infection  is  removed. 

Respiratory  passages  :  These  also  are  lined  by  a  moist  mucous 
membrane,  but  do  not,  contrary  to  expectation,  contain 
many  germs.  The  mucous  lining  of  the  nose  appears  to  be 
endowed  with  remarkable  germicidal  powers,  so  that  under 
normal  conditions  few  bacteria  ever  reach  the  respiratory  tract 
proper.  It  has  been  estimated  that  1500  bacteria  are  in- 
haled every  hour.  Infection  in  tuberculosis,  pneumonia, 
diphtheria,  influenza,  and  the  exanthematous  fevers  occurs 
through  the  respiratory  tract.  It  is  a  Avell-known  fact  that 
pneumonia  usually  follows  a  "cold,''  and  that  frequent  attacks 
of  bronchitis  or  an  attack  of  pneumonia  predispose  to  tuber- 
culosis. Plague  (bubonic)  pneumonia  is  also  acquired  by 
inhalation.  Bacteria  may  also  be  absorbed  from  the  mucous 
membranes  of  the  air-passages  and  enter  the  adjacent  lymph- 
glands.  This  accounts  for  the  finding  of  tubercular  lymph- 
glands  at  the  root  of  the  lung,  and  in  the  anterior  mediastinum, 
without  the  existence  of  pulmonary  tuberculosis. 

Digestive  tract :  In  addition  to  mnny  non-pathogenic  organ- 
isms, the  mouth  may  harbor  also  the  germs  of  tuberculosis, 
diphtheria,  pneumonia,  and  the  staphylococcus  and  strepto- 
coccus. The  saliva  possesses  slight  germicidal  power.  The 
tonsil  may  act  as  the  portal  of  infection  for  tuberculosis. 
Tuberculosis  of  the  cervical  lymph-glands  probably  always 
follows  tonsillar  infection.  An  attack  of  pharyngitis  predis- 
poses to  diphtheria. 


CONDITIONS  MODIFYING   INFECTION.  109 

The  stomachy  because  of  its  acid  reaction,  is  not  a  favorable 
place  for  the  development  of  bacteria.  Sarcinse  are  frequently 
found  in  the  stomach,  eppecially  during  attacks  of  gastritis; 
also  the  bacilli  of  lactic  acid  and  butyric  acid.  The  Opplet^- 
Boas  bacillus  is  found  in  carcinoma  of  the  stomach.  At  one 
time  it  was  believed  to  be  diagnostic  of  this  condition  ;  but 
it  is  not  constant,  and  is  found  also  in  all  diseases  of  the 
stomach  where  the  conditions  are  similar  to  those  found  in 
carcinoma. 

The  intestinal  canal  can  never  be  said  to  be  free  from  bac- 
teria. Some  varieties  are  constant  inhabitants,  especially  the 
Bacillus  coli  communis,  the  Bacillus  lactis  aerogenes  (in  milk- 
drinkers),  and  the  Streptococcus  coli  gracilis.  These  organisms 
are  found  more  often  in  the  large  than  in  the  small  bowel. 
Although  the  colon  bacillus  is  ordinarily  a  non-pathogenic 
organism,  it  may,  under  favorable  conditions,  give  rise  to 
very  severe  and  even  fatal  diarrhoeas.  It  has  frequently  been 
found  in  suppurative  lesions  of  the  intestinal  tract  and  its 
accessory  glands.  It  is  believed  to  be  the  cause  of  ulceration 
and  perforation  of  the  intestine. 

The  occurrence  of  tuberculosis  of  the  mesenteric  and  retro- 
peritoneal lymph-glands  is  evidence  of  the  fact  that  bacteria 
can  and  do  pass  through  the  walls  of  the  intestine  during 
health  without  causing  any  lesion  of  the  intestine.  An  en- 
teritis always  predisposes  to  infection  with  the  Bacillus  typho- 
sus and  the  cholera  spirillum.  Infection  of  the  gastro- 
intestinal tract  follows  the  ingestion  of  infected  food  or  drink, 
or  the  swallowing  of  tubercular  sputum.  Occasionally  syphi- 
lis also  is  transmitted  through  the  gastro-intestinal  tract. 

Genito-urinary  tract :  A  few  unimportant  varieties  are  found 
in  the  acid  secretions  of  the  vagina,  but  this  acidity  is  rather 
a  protection  against  infection.  The  uterus  is  normally  free 
from  bacteria.  On  the  external  genitals  of  both  man  and 
woman  we  find  pus  cocci  and  the  Bacillus  smegmatis,  which 
resembles  the  tubercle  bacillus  so  closely  that  often  it  is  mis- 
taken for  it.  When  the  urine  is  examined  for  tubercle  bacilli, 
this  resemblance  must  not  be  lost  sight  of,  as  the  one  is  sig- 
nificant of  a  serious  lesion,  and  the  other  possesses  no  patho- 
logic significance  whatever. 


110  INFECTION, 

Infection  of  the  genito-urinary  tract  and  the  reproductive 
organs  may  occur  through  the  circulation  or  by  direct  contact 
with  either  pus  cocci,  the  gonococcus,  the  tubercle  bacillus,  or 
the  virus  of  syphilis. 

Infection  with  the  syphilis  virus  may  take  place  through 
the  placenta.  So  too  may  that  of  typhoid,  tuberculosis, 
anthrax,  and  relapsing  fever.  Puerperal  sapraemia  is  an  infec- 
tion of  retained  portions  of  the  placenta  or  fcetal  membranes 
by  the  streptococcus  or  colon  bacillus  (see  also  page  101). 
Intra-uterine  infection  usually  occurs  through  the  placenta. 

The  bladder  and  accessory  organs  may  be  infected  from  the 
urethra,  and  the  infection  may  spread  from  here  to  the  ureters 
and  kidneys.  Infection  of  the  kidney  may  occur  also  from 
the  adjacent  tissues  and  through  the  blood. 

The  canal  of  the  external  ear  contains  many  non-pathogenic 
germs,  especially  the  Micrococcus  cereus  flavus.  They  diminish 
in  number  near  the  tympanum. 

All  these  germs  gain  lodgement  in  or  on  these  various 
sources  of  infection  from  the  air,  food,  drink,  the  soil,  the 
bodies  of  dead  animals,  and  the  excreta  of  persons  sick  with 
an  infectious  disease ;  but  before  infection  can  occur  it  is 
necessary  that  the  bacteria  enter  the  tissues  themselv^es  in 
sufficient  number,  and  that  they  multiply  there,  w^hen  the 
natural  resistance  of  the  body  is  diminished. 

Blood-current :  According  to  Kruse,  bacteria  gain  entrance 
to  the  blood-current  by  : 

1.  Passive  entrance  through  the  stomata  of  the  vessels 

where  the  pressure  of  the  inflammatory  exudate  is 
greater  than  the  intravascular  pressure. 

2.  Entrance  into  a  vessel  in  the  bodies  of  leucocytes. 

3.  Penetration  of  the  vessel-wall  by  the  growth  of  the 

organism. 

4.  Entrance  through  the  lymphatics  either  passively  or 

within  a  leucocyte. 
Elimination  of  bacteria  from  the  blood :  It  has  been  shown 
that  bacteria  eventually  accumulate  in  the  finer  capillaries, 
especially  those  of  the  liver,  spleen,  lungs,  and  bone-marrow. 
From  the  capillaries  they  are  carried  to  the  surrounding 
tissues,  and  finally  to  the  lymph-nodes ;  or  they  are  excreted 


SPECIAL  PHENOMENA   OF  INFECTION.  Ill 

by  tlie  bile  or  su(;cus  entericus ;  or  discharged  by  the  mucous 
membrane  of  the  alveoli  of  the  lungs,  the  tonsils,  etc.  Not 
infrequently  they  are  discharged  through  suppurating  wounds, 
to  which  they  are  conveyed  by  the  leucocytes.  Many  bac- 
teria are  broken  up  in  the  body  and  are  never  excreted.  The 
liver,  through  the  bile,  always  excretes  bacteria.  The  Bacillus 
pyocyaneus,  when  injected  into  the  blood-current,  is  excreted 
by  the  functionating  mammary  gland.  Bacteria  are  excreted 
also  by  the  sweat,  and  by  the  kidneys  (tubercle  and  typhoid), 
when  there  is  a  diseased  condition  of  the  renal  epithelium. 
In  pulmonary  diseases  the  bacteria  are  excreted  largely  by 
the  sputum ;  in  gastro- intestinal  diseases,  by  the  feces. 

Special  Phenomena  of  Infection. 

Agglutination :  Gruber  found  that  the  serum  of  animals 
immune  to  typhoid,  cholera,  etc.,  or  that  of  human  beings 
who  had  recovered  from  typhoid,  when  added  to  a  small 
amount  of  a  culture  of  the  specific  germ,  caused  the  organism 
to  lose  its  motility  and  finally  sink  to  the  bottom  of  the 
test-tube  as  a  flocculent  precipitate.  Gruber  called  this  phe- 
nomenon agglutination,  and  considered  it  a  reaction  of  immu- 
nity. Widal  showed  later  that  it  really  represented  a  reac- 
tion of  the  period  of  infection,  and  that  the  serum  of 
typhoids,  at  the  end  of  the  first  or  beginning  of  the  second 
week  of  the  disease,  gave  the  serum  reaction.  He  concluded 
that  it  represented  a  possible  reaction  of  the  protoplasmic 
substance. 

The  typical  Widal  reaction  is  the  agglutination  of  the 
typhoid  bacilli  when  mixed  with  typhoid  blood.  When  a 
small  amount  of  blood  is  added  to  a  pure  culture  of  typhoid 
bacilli,  the  bacilli  are  seen  to  lose  their  motility  and  to  gather 
in  clumps  or  bunches.  Agglutination  is  not,  however,  char- 
acteristic of  typhoid,  but  is  seen  in  many  other  infectious 
diseases.  If  the  test  is  performed  accurately,  the  result  is 
absolute.  The  test  will  be  described  fully  in  the  chapter  on 
Typhoid  Fever. 

The  agglutinating  substance  is  contained  in  all  normal  and 
pathologic  fluids  of  the  diseased  animal,  and  is  present  through- 


112  INFECTION. 

out  the  coarse  of  the  disease.  Gruber  named  this  substance 
agglutinin.  It  may  be  formed  by  the  action  of  the  bacteria 
on  the  tissues;  or  by  the  resistance  of  the  tissues  to  the 
infection.  The  second  supposition  is  hardly  tenable.  The 
agglutinating  action  may  also  be  obtained  by  the  addition  of 
chemicals  to  the  blood.  Neitlier  the  composition  nor  the 
origin  of  this  substance  has  as  yet  been  determined  definitely. 
It  is  quite  resistant  to  heat  and  chemicals.  Emmerich  and 
Loew  believe  that  agglutination  is  the  first  stage  of  the  bac- 
teriolytic action  of  the  enzymes  produced  by  bacteria. 

Precipitins :  When  typhoid  cultures  are  mixed  with  the 
blood-serum  of  typhoids,  a  precipitate  (non-bacterial)  is  formed 
which  soon  settles,  leaving  a  clear  supernatant  fluid.  The 
same  reaction  is  obtained  with  other  bacteria  and  their  cor- 
responding blood-sera.  The  precipitate  is  called  the  j^re- 
cipitum,  and  the  substance  in  the  blood  which  induces  the 
precipitation  is  called  precipz^in.  The  " anti-sera  "  also  belong 
to  this  class.  The  precipitins  are  very  resistant  to  heat  and 
chemicals.     Nothing  is  known  of  their  chemical  composition. 

Lysins:  Normal  blood-serum  is  bacteriolytic  to  a  slight 
extent,  but  during  the  infection  specific  bacteriolysins  are 
formed,  which  are  bacteriolytic  for  the  specific  germ  and  also 
its  congeners.  The  composition  and  nature  of  these  bodies 
are  likewise  still  a  matter  of  dispute,  but  it  is  strongly  sus- 
pected that  the  lysins  are  the  same  as  the  agglutinins,  although 
by  no  means  identical. 

All  these  various  substances  are  known  as  "  anti-bodies," 
and  are  the  results  of  the  action  of  foreign  proteid  matter  on 
certain  living  cells ;  such  results  are  chemical  substances 
which  have  a  specific  relation  to  the  substance  under  the 
influence  of  which  they  are  produced. 

Pfeiffa-^s  phenomenon:  Pfeitfer  discovered  that  if  cholera 
bacteria  are  placed  in  the  peritoneal  cavity  of  a  guinea-pig 
that  has  been  immunized  to  cholera,  the  bacteria  are  dis- 
solved by  the  peritoneal  fluid.  The  bacilli  become  immotile, 
swell,  and  break  into  small  granules  which  disappear  com- 
pletely. The  reaction  is  specific  not  only  for  cholera,  but 
also  for  typhoid  and  other  organisms.  This  reaction  is  bac- 
teriolytic, and  is  due  to  the  lysins. 


CHAPTEE    XIII. 

IMMUNITY. 

Immunity  is  an  inherent  insusceptibility  to  disease. 

It  is  a  well-known  fact  that  certain  races  and  individuals 
are  not  susceptible  to  some  infectious  diseases,  and  that  others 
are  extremely  susceptible  to  the  same  diseases.  Negroes,  as 
a  race,  are  immune  to  yellow  fever.  White  persons  born  in 
a  yellow  fever  district,  or  who  have  lived  in  one  for  many 
years,  show  a  like  resistance  to  the  disease.  Scarlet  fever 
and  the  other  exanthems,  except  smallpox,  are  very  common 
in  children,  but  are  rarely  seen  in  adults.  One  attack  of 
smallpox  rarely  is  followed  by  a  second  ;  but  if  so,  the  second 
attack  is  a  very  mild  one.  Birds  and  snakes  are  not  suscep- 
tible to  typhoid ;  mice  and  rats,  to  diphtheria ;  and  pigs,  to 
snake-venom. 

The  natural  barriers  to  infection,  such  as  the  unbroken 
skin  and  normal  mucous  membranes,  can  hardly  be  consid- 
ered essential  factors  in  the  production  of  immunity.  The 
protection  offered  by  immunity  is  solely  against  the  bacterial 
causes  of  disease  which  cannot  develop  in  the  body  of  the 
immune.  Or  the  living  organism  possesses  the  power  of 
diminishing  the  virulence  of  the  germ  and  overcoming  its 
toxic  effects.  This  might  be  termed  tissue-endurance.  The 
immunity  usually  exists  against  both  the  germ  and  its  toxin, 
although  not  against  an  unlimited  number  or  quantity  of 
either,  and  especially  not  of  the  latter.  A  susceptibility  may 
exist  to  the  germ,  but  not  to  its  toxin  ;  as,  for  instance,  man  is 
susceptible  to  the  action  of  the  tubercle  bacillus,  but  not  to  its 
product,  tuberculin.  Immunity  is  always  a  relative  condi- 
tion. Fraenkel  says  that  ^'a  white  rat  is  immune  to  anthrax 
in  amounts  sufficiently  large  to  kill  a  rabbit,  but  it  is  perhaps 
not  immune  to  a  quantity  sufficiently  large  to  kill  an  ele- 
phant.'' 

8— Bact.  113 


114  IMMUNITY. 

Immunity  may  be  :  (a)  natural^  the  immunity  of  certain 
individuals  and  races  against  certain  diseases  at  all  times; 
(6)  inherited^  the  transmission  of  immunity  from  the  mother 
to  the  foetus  through  the  placenta,  or  from  the  mother  to  the 
child  through  the  milk  ;  (c)  acquired,  immunity  produced  by 
one  attack  of  the  disease,  or  by  inoculation,  or  by  the  intro- 
duction into  the  body  of  an  artificially  prepared  antitoxin. 

Immunity  may  also  be  :  (1)  passive  or  (2)  active. 

Immunity  is  said  to  be  active  when  the  tissues  of  the  body 
possess  the  resisting  power. 

In  passive  immunity  the  resisting  power  resides  only  in  the 
blood.  It  may  be  produced  by  injecting  the  blood-serum  of 
an  animal  which  is  actively  immune. 

The  immunizing  substance  always  is  stored  up  in  greatest 
quantity  and  for  the  greatest  length  of  time  in  the  organ 
or  tissue  which  would  be  most  seriously  affected  by  the 
disease. 

Natural  immunity  :  It  is  impossible  to  give  an  exact 
definition  of  immunity,  especially  natural  immunity.  Natural 
immunity  is  not  absolute,  although  it  is  more  so  than  the 
acquired  form.  The  cause  of  immunity  is  still  a  matter  of 
conjecture.  The  most  we  can  do  is  to  study  the  conditions 
which  influence  immunity  either  one  way  or  the  other. 
Various  theories  as  to  its  nature  have  been  suggested  : 

Phagocytosis :  The  phagocytic  theory  of  immunity  was 
advanced  by  Metschnikoff.  It  is  based  on  a  peculiar  property 
possessed  by  the  white  corpuscles,  especially  the  polymorpho- 
nuclear leucocytes,  and  certain  fixed  tissue-cells,  the  endothe- 
lial cells.  The  former  are  termed  microphages,  and  the  latter 
macrophages.  These  cells  take  up  or  devour  inert  particles, 
hence  their  name  of  phagocytes.  In  an  inflammation,  the 
leucocytes  rush  to  the  seat  of  the  inflammation,  and  not  only 
wall  off*  the  process,  but  also  assist  in  disposing  of  the  effete 
or  foreign  matter.  Leucocytosis  (an  increased  number  of 
leucocytes)  is  a  prominent  feature  in  nearly  all  the  infectious 
diseases — in  fact,  the  prognosis  is  influenced  largely  by  the 
degree  of  leucocytosis.  Metschnikoff"  observed  that  when  an 
animal  is  injected  with  a  culture  of  bacteria,  the  leucocytes 
are  subsequently  found  to  contaiiT  these  organisms ;  further, 


BODY-JUICES.  115 

that  the  cells  gradually  break  up  the  germs,  apparently  a 
process  of  digestion.  In  an  immune,  phagocytosis  is  usually 
very  active,  whereas  in  a  susceptible  animal  there  is  little  or 
no  phagocytosis. 

The  question  has  been  raised  whether  these  cells  take  up 
living  bacteria  or  whether  they  simply  act  as  scavengers  by 
removing  the  dead  germs.  Metschnikoff  successfully  isolated 
leucocytes  containing  anthrax  spores  and  transplanted  them 
to  bouillon.  The  spores  were  set  free  by  the  death  of  the 
leucocyte  and  developed  rapidly  into  mature  and  active  organ- 
isms. This  observation  has  been  confirmed  by  others.  It 
has  also  been  noted  that  the  leucocyte  does  not  always  destroy 
the  germ,  but  that  this  may  destroy  the  leucocyte.  The 
phagocytes  at  times  exhibit  a  selective  tendency  for  certain 
bacteria. 

The  leucocytes  are  repelled  or  attracted  by  certain  sub- 
stances. This  property  is  known  as  chemotaxis.  Chemotaxis 
is  either  positive  or  negative.  If  positive,  the  chemotactic 
substance  attracts  large  numbers  of  leucocytes,  when  phago- 
cytosis is  very  marked.  In  negativ^e  chemotaxis  the  leuco- 
cytes are  repelled  ;  phagocytosis  is  then  absent.  In  natural 
immunity  positive  chemotaxis  is  very  apparent.  The  leuco- 
cytes probably  kill  the  bacteria  by  digesting  them  or  by  lib- 
erating some  chemical  substance  which  destroys  the  germ. 
This  chemical  substance  may  be  nucleiic  acid  or  nuclease. 
The  phagocytic  theory  of  immunity  is  no  longer  tenable  in 
view  of  the  extensive  researches  made  within  the  last  few 
years.  Phagocytosis  is  now  regarded  as  the  result  rather  than 
the  cause  of  immunity. 

Body -juices :  In  1872  Lewis  and  Cunningham  noted  that 
bacteria  injected  into  the  body  disappeared  completely  within 
a  few  hours. 

Other  investigators,  notably  Fodorand  Nuttall,  in  1887-88, 
demonstrated  that  the  blood  exhibited  decided  germicidal 
powers  for  some  time  after  its  withdrawal  from  the  body. 

The  same  bacteriolytic  action  was  observed  in  other  of  the 
tissue-fluids,  such  as  ascitic  and  hydrocele  fluids,  aqueous 
humor,  etc. 

The  germicidal  power  of  the  blood  is  destroyed  by  heating 


116  IMMUNITY. 

it  to  55°  C;  the  ordinary  blood-serum  culture-medium  illus- 
trates this  destructive  action. 

Germicidal  power  of  the  blood — causes :  This  bacteriolytic 
action  is  especially  marked  in  the  cases  of  those  bacteria  to 
which  the  animal  is  naturally  immune.  There  are  exceptions 
to  this  rule,  however.  The  rabbit  is  very  susceptible  to  anthrax 
even  though  its  blood  is  markedly  germicidal  for  the  anthrax 
bacillus.  It  is  possible  that  this  action  of  the  blood  is  not  so 
much  germicidal  as  attenuating,  thus  antagonizing  the  toxi- 
genic power  of  the  bacterium  and  enabling  the  tissues  to 
dispose  of  the  germ. 

Beliring  attributed  this  germicidal  action  to  the  alkalimty 
of  the  blood.  Buchner,  after  very  exhaustive  studies  of  this 
subject,  concluded  that  the  germicidal  properties  of  tiie  blood 
are  due  entirely  to  its  soluble  constituents,  which  he  termed 
alexins.  Hankin  ascribed  it  to  the  germicidal  globulins, 
which  he  named  defensive  proteids.  They  are  destroyed  by 
heating  to  55'°-60°  C.  for  one-half  hour,  and  by  dihiting 
with  from  eight  to  ten  volumes  of  distilled  water.  Vaughan 
and  McClintock  attribute  the  germicidal  action  to  the  nudeiTis, 
and  believe  that  immunity  diminishes  as  these  substances 
become  less  soluble.  They  extracted  nuclein  from  the  blood- 
serum  and  demonstrated  its  germicidal  property. 

Buchner's  alexins  are  not  nucleins.  The  alexins  are  de- 
rived from  the  leucocytes,  especially  the  amphophiles,  which 
Hankin  calls  the  alexocytes,  Buchner  found  that  when  the 
leucocytes  disintegrated,  a  germicidal  substance  is  liberated, 
showing  that  tlie  germicidal  action  of  the  blood  is  not  due 
to  phagocytosis.  It  is  probable,  therefore,  that  the  living 
leucocyte  secretes  a  substance  on  which  the  so-called  pha- 
gocytic action  depends.  Although  the  exact  nature  and 
composition  of  these  alexins  are  not  definitely  known,  they 
in  all  probability  have  their  origin  in  the  white  cell  of 
the  blood,  in  which  also  resides  the  germicidal  power  of 
the  blood. 

Plasmohfsis  may  also  be  of  some  importance  in  this  con- 
nection. The  removal  of  a  germ  from  an  isotonic  to  a  hyper- 
tonic or  hypotonic  medium  in  all  probability  has  an  injurious 
effect  on  the  organism.     While  this  does  not  account  for  the 


ACCIDENTAL  AND  EXPERIMENTAL  IMMUNITY.     117 

germicidal  property  of  the  blood,  yet  it  may,  to  some  extent, 
be  held  to  account  for  it. 

Immunity  to  the  toxins^  according  to  Ehrlich,  is  due  to  the 
fact  that  some  of  the  tissue-cells  are  capable  of  forming 
chemical  combinations  with  the  toxin  by  means  of  so-called 
molecular  mle-chains ;  that  is,  that  these  substances,  or  side- 
chains,  neutralize  the  toxin  and  thus  allow  the  "  natural  resist- 
ance '^  of  the  system  at  large  to  dispose  of  the  germs.  This 
theory  will  be  discussed  more  fully  later  on  (see  page  122). 

Emmerich  believed  that  bacteria  produce  enzymes  which  are 
capable  of  digesting  not  only  the  germs  that  caused  their  for- 
mation (conforme),  but  also  in  some  cases  other  germs  as  well 
(heteroforme).  The  immune  serum  contains  more  enzymes 
than  do  artificial  cultures  of  bacteria.  These  enzymes  may 
account  also  for  the  degeneration-forms  of  bacteria  seen  in 
old  cultures,  and  for  the  self-limitation  of  infectious  diseases. 
He  calls  these  enzymes  nucleases.  In  order  to  distinguish 
them,  each  enzyme  is  named  after  the  organism  producing 
it,  as  typhase,  pyocyanase,  etc.  An  immune  p^oteidy  accord- 
ing to  Emmerich,  is  a  combination  of  the  enzyme  with  some 
albuminous  body.  He  believes  that  the  bacteriolytic  action 
of  normal  blood  is  due  to  the  presence  of  enzymes. 

Acquired  immunity  :  This  form  of  immunity  is  peculiar 
to  the  individual,  and  is  extremely  variable  in  its  duration. 
It  is  acquired  either  accidentally  or  experimentally,  and  is 
not  a  hereditary  condition. 

Accidental  immunity :  This  usually  results  from  an  attack 
of  an  infectious  disease,  like  scarlet  fever,  smallpox,  measles, 
etc.  Such  an  attack  confers  an  immunity  which  under  ordinary 
conditions  is  permanent.  The  immunity  may,  however,  be  of 
only  short  duration,  after  which  the  individual  is  just  as  sus- 
ceptible to  the  disease  as  he  was  before  the  first  attack.  In 
many  of  the  infectious  diseases  the  immunity  is  of  only  a  few 
months'  duration.  The  attack  which  confers  the  immunity 
need  not  necessarily  be  either  a  severe  or  a  typical  one.  For 
instance,  a  mild  attack  of  smallpox  confers  as  lasting  immunity 
as  a  severe  attack.     This  is  seen  in  vaccination. 

Experimental  immunity :  This  differs  from  the  accidental 
form  in  that  it  is  dependent  upon  purely  artificial  conditions. 


118  IMMUNITY. 

It  is  this  form  of  immunity  which  is  responsible  for  the 
many  conflicting  theories  of  immunity. 

Active  form :  Years  ago,  before  it  even  was  surmised  that 
diseases  might  be  caused  by  minute  vegetable  organisms,  it 
was  observed  clinically  that  one  attack  of  some  diseases  ren- 
dered the  individual  secure  from  a  second.  It  was  customary 
to  produce  artificial  immunity  to  smallpox  by  inoculation. 
A  mild  case  of  the  disease  was  selected,  and  the  healthy  indi- 
vidual was  inoculated,  through  an  abrasion  of  the  skin,  with 
some  of  the  purulent  matter  obtained  from  a  smallpox  pus- 
tule. As  might  be  expected,  with  the  conditions  prevailing 
at  that  time,  the  person  so  inoculated  often  was  the  means  of 
exciting  an  epidemic  by  developing  a  very  severe  case  of 
smallpox,  and  deaths  were  by  no  means  infrequent. 

This  primitive  method  of  inoculation  was  modified  subse- 
quently by  Jenner,  who  noticed  a  peculiar  affection  of  the 
cow's  udder  resembling  smallpox  in  man.  He  also  noted 
that  the  milkmaids  contracted  this  disease,  and  that  afterward 
they  were  immune  to  smallpox.  He  then  inoculated  mem- 
bers of  his  family  with  matter  obtained  from  the  pustules 
on  a  cow's  udder,  and  succeeded  in  producing  immunity  to 
smallpox.  This  form  of  inoculation  is  known  as  vacchiation. 
The  virus  is  attenuated  by  its  passage  through  the  cow,  and 
its  inoculation  into  man  produces  simply  a  local  lesion  with 
slight  constitutional  symptoms,  but  confers  an  immunity  equal 
to  that  following  a  typical  attack  of  smallpox. 

This  form  of  inoculation  is  no  longer  limited  to  smallpox, 
but  is  practised  also  in  anthrax,  symptomatic  anthrax,  cholera, 
bubonic  plague,  and  typhoid  fever.  The  principle  under- 
lying it  is  the  attenuation  of  the  germ  ;  and  many  vaccines, 
viruses,  or  attenuated  cultures,  are  now  being  used  to  produce 
these  results. 

It  is  claimed  that  inoculation  with  sapr^ophytic  bacteria 
derived  from  the  soil  and  water  will  give  protection  against 
pathogenic  organisms.  When  a  culture  of  the  Bacillus  pro- 
digiosus  is  injected  into  a  rabbit  sick  with  anthrax,  the  animal 
will  recover. 

This  form  of  immunity  may  be  secured  by  treating  the 
animal  to  weakened  cultures  of  the  germ  ;  by  injecting  steril- 


EXPERIMENTAL  IMMUNITY.  119 

ized  cultures  or  toxins ;  by  inoculation  with  cultures  of  the 
specific  germ  mixed  with  other  organisms;  with  dead  bacteria; 
with  germs  grown  on  media  containing  an  antiseptic.  Very 
virulent  organisms  are  attenuated  by  growing  them  at  high 
temperatures. 

Immunity  secured  in  this  way  is  of  only  short  duration, 
but  is  sufficient  to  protect  the  individual  against  the  disease 
for  the  time  being. 

The  toxicity  of  the  virus  may  also  be  modified  by  heat- 
ing it;  or  by  the  addition  of  chemicals,  such  as  iodine  or 
chlorine. 

A  certain  amount  of  tolerance  (really  a  form  of  immunity) 
may  be  produced  by  substances  other  than  bacteria.  This  is 
seen  in  many  forms  of  intoxication.  The  fact  that  immunity 
may  be  conferred  not  only  by  pathogenic  bacteria  and  their 
products,  but  also  by  dead  bacteria,  saprophytes,  and  inert 
particles,  forces  us  to  the  conclusion  that  whatever  confers 
the  immunity  is  a  chemical  compound  which  is  distributed 
widely  in  nature.  Calmette  produced  immunity  by  successive 
injections  of  snake-venom.  Ehrlich's  experiments  with  ricin 
and  abrin  were  similarly  successful.  Others  produced  immu- 
nity to  poisonous  eels,  botulismus,  arsenic,  etc.  The  immu- 
nity produced  by  these  substances  is  practically  the  same  as 
bacterial  immunity.  The  immunity  is  due  perhaps  to  phago- 
cytosis or  phagolysis,  and  the  tissue  becomes  enriched  with 
antibacterial  substances. 

Passive  form:  This  form  of  immunity  is  always  experi- 
mental. It  is  produced  by  the  administration  of  antitoxins. 
An  antitoxin  is  a  substance  derived  from  immunized  animals, 
and  which,  when  injected  into  another  animal,  confers  immu- 
nity. A  special  chapter  will  be  devoted  to  the  consideration 
of  these  highly  interesting  substances. 

Tissue-suspensions  are  also  a  source  of  experimental 
immunity.  Wassermann  found  that  the  spinal  cord  of  a 
rabbit  when  crushed  and  suspended  in  a  normal  salt  solution 
and  mixed  with  tetanus  toxin  protected  against  tetanus  even 
when  the  cord  alone  was  injected  either  before  or  after  the 
toxin,  or  into  another  part  of  the  body.  These  findings  have 
been   confirmed   by  others ;   but   it   is   maintained   that  the 


120  IMMUNITY. 

nervous  substance  must  come  into  direct  contact  with  the 
toxin  in  order  to  be  effective  ;  further,  that  it  excited  an 
inflammatory  reaction  at  the  site  of  injection,  and  that  this 
ah)ne  was  responsible  for  the  resulting  immunity.  The  brain 
substance  must  be  crushed,  otherwise  it  is  ineffective.  Marie 
found  that  the  gray  matter  of  the  cerebral  cortex  possessed 
the  greatest  imnmnizing  power.  Immunization  by  tissue- 
suspensions  has  been  practised  for  some  time  against  tetanus 
infection,  but  the  results  have  not  been  very  satisfactory. 
Extracts  of  the  liver  and  the  adrenals  have  been  found  to 
counteract  the  cobra  poison. 

Inert  substances :  By  mixing  commercial  carmine  with 
tetanus  toxin  in  the  proportion  of  0.5  gram  to  10  c.c,  the 
toxicity  of  the  toxin  is  reduced  considerably.  By  heating 
this  mixture  to  60°  C,  its  protective  action  is  destroyed;  but 
twenty-four  hours  afterward  the  mixture  has  regained  its 
toxicity,  so  that  the  toxin  is  not  destroyed  by  the  carmine. 
This  peculiar  action  of  the  carmine  is  probably  the  result  of 
the  leucocytosis  produced  by  tlie  inflammatory  reaction  of 
the  tissues  when  the  mixture  is  injected. 

Modification  of  immunity  :  Inasmuch  as  immunity  is 
at  all  times  only  a  relative  and  not  an  absolute  condition,  we 
will  now  consider  briefly  those  conditions  which  modify 
immunity.  Exaltation  of  immunity  is  synonymous  with 
acquired  immunity,  which  we  have  gone  into  already.  The 
modifications  that  are  of  vital  importance  are  those  which 
tend  to  lessem  the  immunity.  They  ai'e  all  manifested  by  a 
diminution  of  the  resistance  of  the  tissues  to  infection. 

Exposure  to  cold :  This  is  one  of  the  most  potent  agents  in 
the  reduction  of  immunity.  Many  infectious  diseases  follow 
"  taking  cold,''  especially  pneumonia,  tuberculosis,  and  other 
affections  of  the  respiratory  system. 

Fatigue  has  a  decided  tendency  to  reduce  tissue  resistance, 
and  consequently  the  immunity. 

Poor  hygiene :  It  is  a  matter  of  every-day  observation  that 
epidemics  of  infectious  diseases  are  much  more  common  under 
poor  hygienic  conditions  than  where  these  do  not  prevail. 
Living  in  small,  stuffy  rooms  to  which  sunlight  and  fresh  air 
have  little  or  no  access,  overwork,  insufficient  sleep,  worry, 


THEORIES  EXPLAINING  ACQUIRED  IMMUNITY.    121 

anxiety,  fear  and  fright,  and  improper  diet,  all  predispose  to 
infection  by  lessening  immunity. 

Noxious  gases :  The  inhalation  of  noxious  gases  also  tends 
to  diminish  the  condition  of  immunity.  Since  the  perfection 
of  the  sewerage  system,  infectious  diseases  are  not  so  often  the 
result  of  inhalation  of  sewer  gases.  Formerly  many  diseases 
were  supposed  to  have  their  origin  in  the  inhalation  of 
sewer  gas,  especially  diphtheria  and  scarlet  fever ;  but  since 
their  infectious  nature  has  been  established,  it  must  be  evi- 
dent that  these  gases  are  only  operative  in  so  far  as  they 
lessen  the  bodily  resistance,  or  immunity,  to  these  infectious 
diseases.  Modern  sanitation  has  certainly  been  effective  in 
reducing  the  number  of  cases  of  the  diseases  mentioned,  and 
we  must,  therefore,  accept  the  statement  that  noxious  gases 
play  some  part  in  their  production. 

Drugs,  etc. :  Persons  addicted  to  the  use  of  drugs  or  alcohol 
are  much  more  liable  to  infection  than  total  abstainers.  In 
such  individuals  the  disease  usually  manifests  itself  in  its 
worst  form. 

Trauma  and  operations :  These  invariably  reduce  immunity 
by  creating  conditions  most  conducive  to  the  development  of 
bacteria. 

Other  diseases :  Any  chronic  disease  reduces  the  vitality  of 
the  individual,  so  that  he  is  extremely  susce])tible  to  infection. 
His  immune  power  is  all  used  up,  and  he  succumbs  to  the 
terminal  infections,  which  he  would  escape  were  he  in  posses- 
sion of  his  full  powers  of  resistance. 

Mixed  infections :  The  body  appears  to  be  unable  to  take 
care  of  more  than  one  infection  at  a  time.  Its  energies  are 
directed  toward  one  point  of  attack,  and  dissolution  follows 
as  the  result  of  the  other  infection.  Persons  who  have  sur- 
vived an  attack  of  typhoid  or  influenza  succumb  rapidly  to  a 
complicating  pneumonia.  The  two  occurring  together  is  more 
to  be  dreaded  than  either  one  alone. 

Theories  explaining  acquired  immunity  :  Exhaustion 
theory  of  Pasteur  and  Klebs:  In  1880  Pasteur  and  Klebs 
suggested  that  immunity  was  due  to  the  exhaustion  in  the 
body  of  some  substance  necessary  to  the  development  of 
bacteria.     During  the  first  infection  the  germs  consumed  this 


122  IMMUNITY. 

particular  substance,  and  at  the  time  of  the  second  infection 
died  for  want  of  it.  This  theory  is  no  longer  tenable,  as  we 
have  shown  that  even  an  immune  will  succumb  to  an  over- 
whelming infection,  so  that  a  vital  substance  can  have  noth- 
ing to  do  with  the  production  of  immunity. 

Retention  theory:  Chauveau  suggested  that  the  bacteria 
in  the  course  of  their  development  elaborate  some  metabolic 
product  which  accumulates  in  the  body  and  is  retained.  This 
product  is  inimical  to  the  growth  of  that  particular  organism, 
and  a  second  infection  cannot,  therefore,  occur. 

Under  normal  conditions  the  tissues  and  fluids  of  the  body 
are  constantly  undergoing  changes,  and  it  is  extremely 
improbable  that  any  metabolic  product  of  this  kind  could  be 
retained  unchanged  for  an  indefinite  number  of  years.  Fur- 
thermore, it  is  also  improbal)le  that  an  individual  who  has 
suffered  from  a  number  of  different  infections  could  keep 
stored  up  in  his  body  the  products  of  the  various  organisms 
causing  these  infections  in  sufficient  quantity  to  prevent  their 
development  at  a  subsequent  infection. 

Germicidal  action  of  the  body-juices :  It  has  repeatedly  been 
demonstrated  that  freshly  drawn  blood,  aqueous  humor, 
ascitic  fluid,  and  the  lymph  from  the  dorsal  lymph-sac  of  the 
frog,  possess  a  decided  germicidal  power.  This  power  is 
positive,  but  is  limited  as  to  the  number  of  bacteria  which 
can  be  destroyed  by  a  given  quantity  of  serum.  Heat 
promptly  destroys  this  power.  The  theory  is  therefore 
untenable. 

Phagocytosis  :  This  theory  has  already  been  fully  discussed. 

Antitoxins :  When  it  was  discovered  that  bacteria  elabo- 
rated toxins,  the  conclusion  was  arrived  at  that  immunity  to 
these  toxins  must  be  due  to  an  antagonistic  substance  which 
neutralizes  the  toxins.  This  substance  was  called  antitoxin. 
These  antitoxins  are  probably  one  of  the  phenomena  of  immu- 
nity rather  than  the  cause  of  it.  They  will  be  discussed 
fully  in  the  next  chapter. 

Ehrlich's  lateral-chain  theory :  Ehrlich  believes  that  the 
various  cells  of  the  body  contain  a  nucleus  to  which  are 
attached  by  means  of  what  he  terms  ^'  side-chains  "  certain 
atom  groups.     These  side-chains  are  concerned  in  the  nutri- 


THEORIES  EXPLAINING  ACQUIRED  IMMUNITY.     123 

tive  function,  but  appear  to  be  capable  of  combining  with  a 
toxin  by  means  of  haptophorous  bodies, — the  toxopkile  chains 
in  the  cell,  and  the  cytophUe  granules  in  the  toxin  molecule. 
A  second  group  of  granules  in  the  toxin  molecule,  called  the 
toxophore  group  of  granules,  destroys  the  cell  if  they  are 
present  in  sufficient  quantity.  If  present  in  only  a  limited 
quantity,  they  merely  injure  the  cell,  stimulating  it  to  repair, 
and  the  cell  throws  out  new  side-chains.  The  frequent  intro- 
duction into  the  body  of  toxins  results  in  overstimulation  of 
the  cell,  and  consequently  it  throws  out  for  its  protection 
more  side-chains  than  really  are  needed.  This  surplus  or 
overstock  of  side-chains  is  thrown  into  the  circulating  blood- 
current,  lymph,  and  other  body-juices,  and  these  constitute 
the  antitoxin,  which  during  an  infection  combines  with  the 
toxin  and  neutralizes  it.  The  whole  theory  is  based  on  the 
chemistry  of  the  cell,  and  the  so-called  "side-chains"  simply 
represent  chemical  formulae.  There  is  no  experimental  foun- 
dation to  this  theory,  but  it  is  the  most  plausible  of  them 
all,  as  all  the  changes  in  the  body  are  merely  chemical 
changes. 


CHAPTER    XIV. 

ANTITOXINS. 

Those  substances  which  destroy  bacteria  are  said  to  be 
germicidal ;  but  those  substances  which  neutralize  the  bacte- 
rial toxin  are  of  vastly  more  importance.  They  are  called 
antitoxins.  An  antitoxin  is  a  substance  which  has  remained 
in  the  tissues  and  juices  of  the  body,  and  which  confers 
immunity  by  antagonizing  or  neutralizing  the  product  of  the 
bacteria.  The  most  exhaustive  experiments  and  researches 
have  failed  to  reveal  the  exact  nature  of  these  products, 
although  their  presence  in  the  body  has  been  proved  by  many. 

It  is  not  accepted,  however,  that  immunity  is  due  to  the 
presence  in  the  body  of  an  antitoxin.  This  substance  is 
looked  upon  as  the  result  of  forced  immunization. 

Various  theories  as  to  the  probable  nature  of  this  substance 
have  been  advanced.  All  experimental  evidence  goes  to 
show  that  in  certain  conditions  acquired  immunity  depends 
upon  the  formation  of  an  antagonistic  substance.  Antitoxins 
usually  possess  no  germicidal  power. 

Buchner  does  not  regard  the  antitoxin  as  a  reactive  prod- 
uct, but  as  a  modified,  changed,  '^  poison-free "  product  of 
the  specific  bacterial  cells. 

Ehrlicli's  side-chain  theory  is  another  theory  accounting  for 
the  production  of  the  antitoxin,  that  it  is  the  product  of 
excessive  tissue  stimulation. 

For  a  long  time  it  was  supposed  that  the  antitoxin  was  the 
modified  toxin,  but  conclusive  evidence  against  this  theory  is 
now  at  hand  :  (1)  The  quantity  of  antitoxin  is  not  at  all  in 
proportion  to  the  amount  of  toxin  required  to  produce  the 
immunity.  (2)  The  removal  of  large  quantities  of  blood  from 
the  body  does  not  lessen  the  degree  of  immunity.  (3)  If  the 
immune  animal  is  bled  to  death  and  the  entire  vascular  system 
carefully   washed  out  with   sterile  salt  solution   until  every 

124 


CHEMICAL  COMPOSITION,  125 

possible  bit  of  blood  is  removed,  infusions  of  certain  tissues 
will  still  be  found  to  contain  the  antitoxin. 

It  has  been  claimed  that  a  toxin  can  be  converted  into  an 
antitoxin  by  means  of  electricityy  but  Vaughan  and  Novy  dis- 
proved this. 

The  bacteria  themselves  are  not  responsible  for  the  produc- 
tion of  the  antitoxin  ;  they  simply  elaborate  the  tx)xin,  whicli 
must  be  held  responsible  for  the  production  of  the  antitoxin. 

Emmerich  and  Loew  believe  that  the  bacterial  enzymes  are 
really  the  antitoxin.  These  enzymes  are  not  eliminated,  but 
accumulate  in  the  blood,  thus  conferring  the  immunity. 
Experimental  investigation  has  disproved  this  theory.  The 
quantity  of  enzymes  formed  is  insufficient  to  account  for  the 
large  amount  of  antitoxin. 

Hankin  calls  the  antitoxic  substances  defensive  proteids. 
He  classifies  them  according  to  the  method  of  their  produc- 
tion and  their  action  on  either  the  toxin  or  the  germ.  Those 
found  in  animals  that  are  naturally  immune  he  has  named 
sozines.  The phylaxins  are  responsible  for  artificial  immunity. 
The  prefixes  myco-  and  toxo-  are  used  to  indicate  whether  the 
defensive  action  is  against  the  germ  or  its  toxin.  These 
proteids  are  the  same  as  those  Buchner  terms  alexins.  They 
probably  are  retained  within  the  bloodvessels  for  an  indefi- 
nite length  of  time,  as  they  do  not  dialyze.  Yet  Ehrlich 
has  shown  that  tetanus  antitoxin  is  excreted  by  the  mother's 
milk  without  in  the  least  lessening  the  immunity  of  the 
mother,  thus  making  it  extremely  probable  that  there  is  a 
continuous  production  of  the  protective  material. 

The  chemical  composition  of  the  antitoxic  substances  is  not 
known,  except  that  they  are  extremely  stable.  They  are  much 
more  resistant  than  the  alexins.  When  exposed  to  a  tempera- 
ture of  60°  C.  for  a  short  time  only,  they  remain  unchanged. 
They  resist  putrefaction,  artificial  light,  and  sunlight,  and 
can  be  kept  for  a  long  time.  The  various  antiseptics 
usually  added  to  the  antitoxic  sera  do  not  affect  them  in  any 
way,  and  are  added  simply  to  prevent  contamination  and 
putrefaction.  The  antitoxins  are  very  resistant  to  carbolic 
acid,  trikresol,  chloroform,  and  formaldehyde.  The  addition 
of  alcohol  precipitates   the  albumins  and  deprives  the  serum 


126  ANTITOXINS. 

of  its  antitoxic  power.  When  taken  by  moutli,  the  anti- 
toxins are  digested  in  the  alimentary  canal,  because  of  their 
proteid  composition,  without,  however,  conferring  immunity. 
It  is  impossible  to  obtain  antitoxin  in  a  pure  form. 

Specific  action  of  antitoxin :  The  action  of  certain  antitox- 
ins is  specific.  The  diphtheria  antitoxin  protects  against  the 
diphtheria  bacillus  and  its  toxin  only.  Hueppe  claims  that 
specific  antitoxins  also  protect  against  other  infections, 
although  in  a  less  degree.  Antitoxins,  as  a  rule,  are  effective 
only  against  the  toxin  and  not  the  germ  as  well,  unless  the 
immunization  has  been  produced  by  the  use  of  active  cultures 
of  the  germ.  The  action  of  the  antitoxin  may  be  due  to  a 
direct  chemical  combination  with  the  toxin,  forming  an  inert 
mixture ;  or  indirectly  by  a  stimulation  of  the  activity  of  the 
tissue-cells  by  the  antitoxin.  It  may  also  act  through  a  com- 
bination of  the  antitoxin  with  the  toxin  through  the  medium 
of  the  combining  substances  or  ferments  in  the  blood. 

Manufacture :  Antitoxin  is  now  being  manufactured  on  a 
large  scale  for  the  purpose  of  producing  artificial  immunity 
against  certain  infectious  diseases,  and  also  for  use  as  a 
thera})eutic  agent.  The  method  consists  in  immunizing  large 
animals,  principally  horses,  by  huge  quantities  of  toxin,  and 
then  withdrawing  a  certain  quantity  of  blood  when  the 
desired  degree  of  immunity  has  been  attained.  The  prepara- 
tion of  the  specific  antitoxins  will  be  considered  in  the  chap- 
ters on  the  infectious  diseases. 

The  exact  strength  of  the  serum  must  be  determined  before 
it  can  be  used  either  for  immunizing  purposes  or  therapeuti- 
cally. The  amount  of  antitoxin  required  to  protect  25,000 
grams  weight  of  guinea-pigs  from  the  minimal  fatal  dose  of 
toxin  is  called  an  immunizing  unit.  Usually  from  600  to 
1800  immunizing  units  are  required  to  produce  a  cure.  This 
amount  is  contained  in  2,  4,  or  6  c.c.  of  commercially  pre- 
pared antitoxin. 

Method  of  administration :  It  is  useless  to  administer  anti- 
toxins by  mouth,  because,  as  already  mentioned,  they  are 
digested  in  the  intestinal  canal.  Therefore  they  always 
are  administered  by  hypodermic  injection  into  the  subcu- 
taneous tissues.     It  really  does  not  matter  where  the  injec- 


METHOD   OF  ADMINISTRATION. 


127 


tion  is  made,  providing  the  site  of  injection  contains  much 
loose  subcutaneous  tissue  and  is  capable  of  absorbing  the 
fluid  rapidly.  It  is  also  desirable  to  choose  a  site  that 
is  not  exposed  to  pressure  by  the  clothing  or  by  the  posi- 
tion of  the  patient,  and  in  which  the  nerve-supply  is  not 
very  great.  Jf  an  injection  is  made  into  a  part  of  the 
body  which  is  well  supplied  with  nerves,  the  injection  is 
attended  by  considerable  pain.  This  should  always  be 
avoided.     The   places   usually   chosen  for   injection  are  the 

Fig.  37. 


Syringe  for  injecting  antitoxin. 


flank,  the  tissues  of  the  back  between  the  shoulder-blades, 
or  the  outer  aspect  of  the  thigh.  In  the  case  of  refractory 
patients  the  most  convenient  place  is  chosen.  It  is  not 
necessary  to  inject  the  antitoxin  in  the  vicinity  of  the  lesion. 
An  injection  of  antitoxin  should  be  given  with  the  same 
antiseptic  precautions  as  any  ordinary  injection.  The  skin  is 
sterilized  carefully  and  thoroughly,  and  the  needle  of  the 
syringe  (Fig.  37)  is  made  aseptic  by  boiling  for  fifteen  minutes. 
The  antitoxin  container  is  broken,  the  syringe  filled,  and  the 


128  ANTITOXINS. 

needle  carefully  introduced  into  the  subcutaneous  tissues.  As 
the  injection  is  made  the  needle  is  withdrawn  slowly  and 
gradually,  and  the  opening  sealed  with  collodion.  Slight 
manipulation  of  the  part  will  facilitate  absorption  of  the  serum. 

Many  of  the  ill-effects  following  the  administration  of 
antitoxin  are  due  to  careless  technique  and  lack  of  suffi- 
cient cleanliness.  Localized  suppuration,  septicaemia,  and 
pyaemia  are  quite  likely  to  follow  careless  injection.  The 
patient  should  be  absolutely  quiet  while  the  injection  is  made, 
so  that  the  needle  of  the  syringe  will  not  penetrate  any  further 
than  into  the  subcutaneous  tissues.  In  the  case  of  children, 
it  is  best  to  wrap  them  in  a  sheet  or  large  cloth,  leaving  only 
the  site  of  injection  exposed.  The  child  is  held  firaily  by  an 
assistant  to  prevent  its  struggling. 

Immunization :  Immunization  is  the  process  of  rendering 
immune.  It  usually  implies  forced  immunity  or  the  gradual 
production  of  immunity  by  the  repeated  injection  of  carefully 
graded  doses  of  toxin.  Any  animal  may  be  used  for  this 
purpose,  but  some  large  animal,  like  the  horse,  is  preferable, 
because  a  larger  amount  of  blood  can  be  withdrawn  at  one 
time.  The  animal  must  be  free  from  tuberculosis  or  glanders 
or  any  other  infectious  disease,  and  should  be  kept  in  a  clean, 
aseptic  stable,  and  be  well  cared  for.  Living  cultures,  attenu- 
ated cultures,  dead  cultures,  filtered  cultures,  or  the  toxin,  are 
used  for  this  purpose. 

The  animal  is  injected  first  with  a  very  small  dose  of  the 
substance  used,  in  order  to  ascertain  its  susceptibility  to  the 
poison.  After  it  has  recovered  from  the  effects  of  this  first 
injection  a  larger  dose  is  given.  This  is  repeated  at  intervals 
until  the  animal  shows  no  reaction  whatever  to  hundreds  of 
times  the  original,  fatal  dose.  This  indicates  a  condition  of 
tolerance,  or  what  might  be  termed  a  toxin-habit,  and  results 
in  a  very  high  degree  of  immunity.  The  immunization  must 
be  carried  on  judiciously.  Care  must  be  taken  not  to  exhaust 
the  tolerance  of  the  animal,  as  a  condition  of  hypersensitivity 
may  be  produced  to  which  the  animal  usually  succumbs. 
There  is,  in  short,  a  limit  to  the  tolerance  of  the  animal, 
and  this  limit  must  not  be  passed.  The  serum  of  highly 
immunized  horses  is  most  suitable  for  therapeutic  purposes. 


IMMUNIZATION.  129 

A  lower  serum  standard  is  sufficient  for  protective  purposes. 
Larger  amounts  of  the  antitoxic  serum  must  be  used  to  pro- 
duce a  cure  than  for  immunization  against  infection. 

When  the  horse  possesses  the  desired  tolerance,  the  jugular 
vein  is  laid  bare  under  antiseptic  precautions  and  a  sterile 
trocar  thrust  into  the  vein.  The  blood  is  collected  in  sterile 
bottles,  and  after  it  has  coagulated  it  is  placed  on  ice  for  a 
few  days,  when  the  clear  supernatant  serum  is  pipetted  off 
with  sterile  pipettes.  This  serum  contains  the  antitoxic  sub- 
stance, and  is  known  as  the  "antitoxin.''  The  serum  is  then 
standardized  and  placed  in  glass  containers,  which  are  steril- 
ized and  then  hermetically  sealed.  It  is  customary  to  add  some 
preservative  to  the  serum.  A  0.5  per  cent,  solution  of  car- 
bolic acid,  camphor,  or  formalin,  or  a  0.4  per  cent,  solution 
of  trikresol,  is  used  for  this  purpose.  Trikresol  is  the  most 
preferable,  as  it  is  not  irritating  and  possesses  slight  anaesthetic 
properties. 

9— Bact. 


CHAPTER   XV. 

EXAMINATION  OF  AIR,  WATER,  AND   SOIL. 

Bacteria  in  the  air :  Both  pathogenic  and  non-pathogenic 
bacteria  are  constantly  present  in  the  air  in  greater  or  less 
number,  depending  on  conditions  and  the  quality  of  the  air. 
The  pure  air  of  the  mountains  contains  very  few  organisms, 
whereas  the  dust-laden  air  of  cities  and  towns  contains  very 
many. 

The  species  also  vary  according  to  the  temperature  and  the 
soil  over  which  the  air  passes,  the  number  of  living  creatures 
moving  about  in  it,  and  their  method  of  living,  hygiene,  and 
sanitation,  the  presence  of  decomposing  material  or  the  excreta 
of  persons  and  animals  affected  with  some  disease.  The  air 
in  sick-rooms  and  hospital  wards  contains  more  organisms 
than  the  outside  air.  The  air  of  places  frequented  by  con- 
sumptives, who  expectorate  promiscuously  on  the  ground, 
usually  is  laden  with  tubercle  bacilli.  During  those  seasons 
of  the  year  when  certain  infectious  diseases,  such  as  pneu- 
monia, la  grippe,  etc.,  are  epidemic,  the  air  is  more  liable  to 
contain  pathogenic  organisms  than  when  such  epidemics  are 
not  prevailing. 

Under  ordinary  conditions,  however,  the  air  usually  con- 
tains only  saprophytic  bacteria,  and  these  are  found  always  in 
the  lower  strata  unless  disseminated  by  winds.  There  are 
less  bacteria  found  in  the  air  during  winter  than  in  the  sum- 
mer, and  very  few  immediately  after  a  rainfall  or  snowfall. 
The  dust  which  is  shaken  from  the  hides  and  pelts  of  animals 
is  very  liable  to  contain  anthrax  bacilli  and  their  spores. 

In  addition  to  the  bacteria,  \we  find  also  moulds  and  yeasts. 

The  presence  of  micro-organisms  in  the  air  is  determined 
easily  by  exposing  a  dish  containing  sterile  gelatin  or  agar  for 
a  few  minutes.     Special   media  must  be  provided  for  those 

130 


EXAMINATION  OF  AIR,    WATER,   AND  SOIL.  131 

germs  which  do  not  grow  on  ordinary  media.  Large  numbers 
of  colonies  of  bacteria  soon  make  their  appearance. 

Besides  determining  the  actual  presence  of  these  germs, 
quantitative  tests  must  be  made.  Various  methods  have  been 
suggested  : 

Hesse  draws  a  current  of  air  through  a  glass  tube  70  cen- 
timeters long  and  3.5  centimeters  wide,  which  is  coated  on 
the  inside  with  a  film  of  gelatin,  like  an  Esmarch  roll  culture. 

Petri  uses  small  sand  filters  placed  in  a  wide  glass  tube 
(Fig.  38).     The  sand  is  first  sifted,  then  sterilized  by  heat, 

Fig.  38. 


Petri's  apparatus  for  bacteriologic  analysis  of  air :   a,  tube  packed  with  sand ; 
arrows  indicate  entrance  and  exit  of  air  current. 

after  which  it  is  placed  in  the  tube,  supported  by  small  wire 
baskets.  Two  such  filters  are  placed  in  one  tube.  One  end 
of  the  tube  is  closed  with  a  cork,  through  the  centre  of  which 
passes  a  thin  glass  tube.  The  entire  apparatus  is  then  steril- 
ized in  the  hot-air  sterilizer.  By  means  of  an  air-pump, 
100  liters  of  air  are  aspirated  through  the  sand  in  from  ten 
to  twenty  minutes.  The  sand  filters  are  then  placed  in  sterile 
dishes  containing  gelatin,  and  the  colonies  are  counted  as 
they  develop.  The  objection  to  this  method  is  that  the  sand 
granules  are  apt  to  be  mistaken  for  colonies. 

Tucker  and  Sedgwick  (Fig.  39)  have  improved  this  method 


132         EXAMINATION  OF  AIR,    WATER,  AND  SOIL. 

by  using  sugar  instead  of  sand.  After  the  air  has  been 
forced  in  at  b  the  cotton  plug  is  replaced  and  through  the 
large  opening  c,  sterile  gelatin  is  poured  into  the  tube,  which 
dissolves  the  sugar ;  and  an  Esmarch  roll  is  made  at  e. 

Uifelmann  found  that  in  the  open  country  1  cubic  meter 
of  air  contains  250  germs ;  on  the  seacoast,  100 ;  in  the  court- 

FiG.  39. 


^  e  '  dab 

The  Sedgvrick-Tucker  aerobioscope :  a,  brass  wire  gauze  stopper ;  c  and  h,  cotton 
stoppers ;  d,  sugar ;  e,  site  for  Esmarch  roll.    (Abbott.) 

yard  of  the  University  of  Rostock,  450.  The  number  was 
less  after  a  rainfall,  and  greater  on  a  windy  day.  These  find- 
ings have  been  verified  by  others. 

It  must  be  remembered,  however,  that  most  of  these  organ- 
isms are  not  pathogenic.  The  number  of  bacteria  found  in 
the  air  is  of  little  clinical  importance  unless  they  are  patho- 
genic. 

Examination  of  Water. 

Water  which  contains  even  a  trace  of  organic  matter  always 
contains  bacteria.  Bacteria  will  not  grow  in  water  free  from 
organic  matter,  although  they  may  remain  alive  in  it  for  a  con- 
siderable time.  The  bacteria  contained  in  water  are  usually 
of  the  non-pathogenic  variety.  At  times,  however,  both  the 
Bacillus  typhosus  and  the  spirillum  of  cholera  may  be  found 
in  water.  More  bacteria  are  found  in  water  after  a  rainfall 
than  before,  because  the  rain  has  washed  them  out  of  the  air 
into  the  water.  Warm  water  contains  more  bacteria  than  cold 
water ;  shallow  water  more  than  deep  ;  water  at  rest  or  having 
only  a  sluggish  current  more  than  running  water;  unfiltered 
more  than  filtered  water.  Inasmuch  as  water  plays  such  an 
important  part  in  the  human  economy,  the  bacteria  which  it 
contains  are  of  more  than  passing  interest,  and  especially  at 
such  times  when  the  water-borne  diseases  are  epidemic. 


EXAMINATION  OF   WATER.  133 

Water  collected  for  bacteriologic  examination  should  be  ex- 
amined as  soon  as  possible,  as  the  contained  bacteria  multiply 
very  rapidly.  An  examination  made  twenty-four  hours  after 
collection  will  not  give  the  same  results  as  an  examination 
made  within  a  few  hours.  \Yarm  water  should  be  examined 
immediately.  The  sample  may  be  placed  on  ice,  but  it  has 
been  found  that  extreme  cold  is  fatal  to  some  of  the  germs. 
Ice  taken  from  water  which  contains  bacteria  usually  contains 
the  same  germs  as  the  water.  The  quality  of  the  water  is  not 
affected  by  the  presence  of  large  numbers  of  non-pathogenic 
germs,  but  a  few  pathogenic  organisms  suffice  to  make  the 
water  an  element  of  danger.  Lake- water  contains  less  bac- 
teria than  river-water.  Wells  having  a  very  deep  supply 
contain  very  few  bacteria,  unless  contaminated  by  the  surface- 
flow.  Very  deep  wells  and  springs  may  contain  no  bacteria 
at  all.  Sewer-water,  of  course,  contains  immense  numbers 
of  bacteria. 

Bolton  showed  that  two  varieties  of  non-pathogenic  bacteria 
occur  in  water  which  has  been  sterilized  as  often  as  six  times. 

Fig.  40. 


Glass  bulb  for  collecting  samples  of  water. 

The  most  important  pathogenic  bacteria  found  in  water  are 
the  typhoid  and  the  cholera  organisms.  These  germs  find 
their  way  into  the  water-supply  from  the  ground-water.  The 
feces  and  other  excreta  containing  these  germs  are  not  disin- 
fected before  they  are  disposed  of,  and  when  they  are  thrown 
on  the  ground  the  germs  make  their  way  into  the  substrata 
of  the  soil,  w^hence  they  are  carried  by  the  ground-water  to 
the  water-supply.  These  organisms  retain  their  vitality  in 
w^ater  for  from  seven  to  thirty  days,  but  do  not  multiply. 
The  non-pathogenic  bacteria  contained  in  water  soon  destroy 
these  pathogenic  bacteria.  The  typhoid  bacillus  will  retain 
its  vitality  for  tliirty  days  in  ice. 

Samples  of  water  may  be  collected  in  sterilized  Erlenraeyer 


134         EX  A  LUNATION  OF  AIR,    WATER,  AND  SOIL. 


flasks,  in  sterilized  bottles  having  a  ground-glass  stopper, 
or  in  Sternberg  bulbs  (Fig.  40).  If  the  city  water-supply  is 
to  be  examined,  the  sample  may  be  taken  directly  from  a 
faucet  after  the  water  has  been  running  for  about  half  an 


Fig.  41. 


Fig.  42. 


•:   :. ;„„„  ,11  f^ 

livENTZStSONS 


Bulb  pipette. 


Fig.  43. 


Bottle  for  collecting  water. 


IT 

Graduated  pipette. 


hour.  If  from  other  sources,  the  container  is  placed  at  the 
depth  at  which  it  is  desired  to  make  the  examination.  The 
bottle  is  uncorked  and  corked  under  the  water,  and  hermeti- 
cally sealed  before  it  is  transported  (Fig.  41).  Only  sterile 
flasks  or  bottles  are  used  for  collection. 


EXAMINATION  OF   WATER. 


135 


Plate  cultures  or  Esmarcli  rolls  are  made  on  gelatin,  agar, 
or  glycerin-agar.  If  the  water  contains  many  bacteria  per 
cubic  centimeter,  it  is  necessary  to  dilute  the  water  with  sterile 
water ;  or  use  only  a  small  quantity  for  the  inoculation  by 
means  of  pipettes  (Figs.  42  and  43). 

Wolfhuegel  counts  the  colonies  by  placing  the  dish  or  plate 
on  a  large  plate  of  glass  (Fig.  44)  divided  into  many  small 

Fig.  44. 


Wolffhuegel's  apparatus  for  counting  colonies. 

squares.  The  colonies  in  a  certain  number  of  squares  are 
counted  with  the  aid  of  a  hand  lens  (Fig.  45),  and  the  num- 
ber of  bacteria  per  cubic  centimeter  estimated  accordingly. 

Fig.  45. 


Lens  for  counting  colonies     (Abbott.) 


If  the  dilution  has  been  sufficient,  only  a  small  number  of 
colonies  appear,  and  these  are  easily  counted.  Divide  the 
result  by  the  number  of  squares  counted,  and  multiply  this 
average  by  the  number  of  square  centimeters  in  the  plate. 
The  result  is  the  entire  number  of  colonies  which  have  devel- 
oped from  the  quantity  of  water  used.  Or  Pakes's  apparatus 
may  be  used  :  a  black  disk,  ruled  with  white  lines  (Fig.  46), 
is  printed  on  a  sheet  of  white  paper ;  a  Petri  dish,  containing 
the  colonies,  with  the  cover  removed,  is  then  placed  over  the 


136 


EXAMINATION  OF  AIR,    WATER,   AND  SOIL. 


disk  and  the  colonies  are  counted  as  they  lie  between  the 
white  lines. 

Ordinary  hydrant- water  usually  contains  from  2  to  50  bac- 
teria per  cubic  centimeter ;  filtered  river-water,  from  50  to 
200;  unfiltered  river-water,  from  6000  to  20,000;  ground- 
water may  contain  as  many  as  130,000. 

An  Esmarch  roll  culture  may  also  be  used,  but  is  most  ser- 
viceable when  the  sample  of  water  contains  but  few  bacteria. 


6  8 

Pakes's  apparatus  for  counting  colonies  (reduced  one-third).    (Abbott.) 


The  surface  of  the  tube  (Fig.  47)  is  divided  into  squares,  and 
the  colonies  counted  with  a  hand  lens  and  estimated  as  in  the 
plate  culture. 

Inasmuch  as  all  water  contains  liquefying  bacteria,  cult- 
ures are  made  on  both  gelatin  and  agar.  The  Bacillus  coll 
communis  is  frequently  found  in  sewage-water  and  in  the 
water  into  which  sewage  empties.       It  is  detected    readily 


EXAMINATION  OF  WATER.  137 

by   making   the    fermentation-test   (Fig.   48).     Occasionally 
other  fermentative  bacteria  are  found  in  water. 

Fig.  47. 


Esmarch  apparatus  for  counting  colonies  in  rolled  tubes.    (Abbott.) 
Fig.  48. 


Flask  for  counting  colonies  of  bacteria. 

The   method   usually   employed   for  isolating  the  typhoid 

bacillus  from  water  is  that  of  Pariette.  He  uses  the  follow- 
ing solution  : 

Phenol,  5  grams ; 

Hydrochloric  acid,  4      " 

Distilled  water,  100  c.c. 


138         EXAMINATION  OF  AIR,    WATER,  AND  SOIL. 

From  0.1-0.2-0.3  c.c.  of  this  solution  are  added  to  10  c.c. 
of  bouillon  in  each  of  three  test-tubes.  Add  from  1  to  3 
c.c.  of  the  water  to  be  examined  to  each  tube,  and  place  in 
the  incubator.  The  only  bacteria  which  will  develop  in  this 
medium  are  the  typhoid  and  colon  bacilli.  These  are  then 
plated  and  separated  (see  Bacillus  typhosus). 

Abbott  suggests  the  use  of  chemical  coagulants,  like  alum 
or  iron,  which,  by  precipitating  as  hydroxides,  drag  down  the 
bacteria.  The  precipitate  is  then  examined.  Or  large  quan- 
tities of  water  are  passed  through  a  Pasteur  filter,  and  the 
accumulations  on  the  filter  brushed  off  and  examined.  The 
water  may  contain  only  a  few  typhoid  bacilli,  and  it  may  be 
necessary  to  make  numerous  examinations  before  their  pres- 
ence is  detected. 

Examination  of  the  Soil. 

Soil  to  the  depth  of  four  feet  always  contains  bacteria, 
especially  when  it  contains  much  organic  matter.  The  upper 
strata  of  virgin  soil  contain  the  greatest  number.  From  the 
surface  down  there  is  a  gradual  falling  off  in  the  number, 
until  at  the  depth  of  four  feet  they  disappear  entirely.  In 
cultivated  soil  and  in  soil  in  which  fertilizers  have  been  used, 
bacteria  are  present  in  great  numbers.  In  inhabited  locali- 
ties the  upper  strata  contain  many  varieties.  Sandy  soil  con- 
tains fewer  bacteria  than  a  clay  soil.  Most  of  the  organisms 
found  in  soil  are  non-pathogenic.  The  pathogenic  bacteria 
are  of  the  anaerobic  variety,  such  as  the  bacillus  of  malignant 
oedema  and  the  tetanus  bacillus.  The  nitrifying  bacteria 
contained  in  soil  are  of  value.  They  decompose  the  organic 
matter  and  convert  it  into  suitable  food  for  the  higher  ])lants. 
That,  as  stated  before,  is  the  reason  the  farmer  turns  under 
several  crops  of  clover  before  sowing  his  grain. 

Ravenel,  in  an  exhaustive  article  on  this  subject,  comes  to 
the  following  conclusions  : 

1.  Made  soil,  as  commonly  found,  is  rich  in  organic  matter 
and  excessively  damp  through  poor  drainage. 

2.  Made  soil  furnishes  conditions  more  suited  to  the  multi- 
plication of  bacteria  than  virgin  soils,  unless  the  latter  are 
contaminated  by  sewage  or  offal. 


EXAMINATION  OF  THE  SOIL.  139 

3.  Made  soils  contain  large  numbers  of  bacteria  per  gram 
of  many  different  species,  the  deeper  layers  being  as  rich  in 
the  number  and  variety  of  organisms  as  the  upper  layers. 
After  some  years  the  number  in  the  deeper  layers  probably 
becomes  less.  Pathogenic  bacteria  are  more  likely  to  be  con- 
tained in  made  soils. 

The  earth  may  be  obtained  at  any  depth  by  means  of 
Fraenkel's  special  boring  apparatus.  A  definite  amount  of 
soil  is  mixed  with  liquefied  gelatin  or  agar  and  a  plate  or 
roll  culture  made.  The  colonies  are  counted  in  the  same  way 
as  in  the  examination  of  air  or  water. 

Fluegge  found  about  100,000  colonies  in  a  cubic  centime- 
ter of  virgin  soil.  Sternberg  advises  washing  the  earth  with 
sterile  water,  and  after  sedimentation  a  sterile  medium  is 
inoculated  with  the  water.  Miquel  found  900,000  colonies 
in  one  gram  of  earth  obtained  from  a  fertilized  field.  One 
investigator  examined  the  soil  of  a  churchyard,  and  found 
1,152,000  bacteria  at  a  depth  of  four  meters.  The  specimens 
of  earth  should  be  examined  as  promptly  as  possible,  so  as  to 
avoid  contamination,  and  also  because  of  the  rapid  develop- 
ment of  the  contained  organisms  when  in  contact  with  oxygen 
and  more  suitable  environments. 


PART  II. 


CHAPTER   I. 

NON-PATHOGENIC  BACTERIA. 

The  study  of  the  non-pathogenic  bacteria  is  of  interest 
largely  from  a  commercial  point  of  view,  as  many  of  these 
organisms  play  a  very  important  part  in  the  manufacture 
of  certain  articles  of  food. 

In  the  bacteriologic  laboratory  it  is  convenient  to  begin 
the  study  of  bacteria,  and  the  methods  of  their  culture  and 
development,  with  the  non-pathogenic  group,  because  most 
students  are  inclined  to  underestimate  the  danger  involved  in 
handling  bacteria  and  the  possibility  of  infection.  The  study 
of  the  pathogenic  bacteria  is  not  taken  up  until  the  technique 
has  been  mastered. 

The  non-pathogenic  bacteria  are  so  numerous  that  it  is 
impossible  in  a  work  of  this  size  to  consider  them  all  or  at 
any  length.  We  shall  limit  the  enumeration  to  such  of  these 
organisms  which  are  either  very  common;  or  which,  because 
of  their  resemblance  to  important  pathogenic  bacteria,  are 
noteworthy.  Furthermore,  the  student  can  easily  obtain  pure 
cultures  of  these  germs  for  laboratory  study.  Most  of  tlie 
non-pathogenic  bacteria  are  found  either  in  water  or  in  the  air. 

Bacillus  subtilis :  One  of  the  most  common  varieties  is  the 
Bacillus  subtilis  or  hay  bacillus.  It  is  found  in  hay  infusions, 
water,  soil,  air,  feces,  and  decomposing  liquids.  Cultures  are 
obtained  very  easily,  and  particularly  when  not  wanted. 
Most  of  the  culture  contaminations  which  occur  in  the  labora- 
tory are  with  the  hay  bacillus. 

The  hay  bacillus  is  a  thick  rod,  about  three  times  as  long 
as   broad,  with    rounded   ends,  and   resembles   the   anthrax 

141 


142 


NON-PATHOGENIC  BACTERIA. 


bacillus  very  closely.  It  frequently  shows  in  its  centre  a 
large,  resistant  spore.  It  occasionally  forms  chains  of  vary- 
ing length.  It  possesses  terminal  flagella;  is  exceedingly 
motile ;  and  is  a  strict  aerobe,  growing  very  rapidly  at  the 
room  temperature  and  upon  all  ordinary  culture-media. 
Luxuriant  growths,  white  in  color,  are  formed,  with  lique- 
faction of  the  gelatin.  It  is  stained  readily  with  the  anilin 
dyes. 

The  organism  can  be  obtained  in  pure  culture  by  making 
an  infusion  in  water  or  beef-tea  with  finely  cut  hay.  Boil  for 
fifteen  minutes,  and  then  place  in  the  incubator  for  forty- 
eight  hours.  The  resistant  spores,  which  have  survived  the 
boiling,  develop  into  fully  matured  germs  and  form  a  thick 
white  scum  on  the  surface  of  the  liquid. 

Bacillus  mesentericus  vulgatus :  This  germ,  known  also  as 
the  potato  bacilluSy  is  found  on  potatoes,  on  the  ground,  and 


Fig.  49. 


Fig.  50. 


Bacillus  mesentericus  vulgatus. 


occasionally  in  milk.  It  is  a  very  short,  thick  rod,  with 
rounded  ends,  frequently  occurring  in  pairs  (Fig.  50).  It 
has  terminal  flagella,  is  excessively  motile,  and  reproduces 
itself  by  sporulation.  It  stains  with  the  anilin  dyes  and  also 
by  Gram's  method.  It  is  strongly  aerobic,  growing  quite 
rapidly  at  the  room  temperature,  especially  in  the  presence 
of  oxygen. 

Gelatin  is  liquefied  ;  milk  is  coagulated.  On  potato  a  heavy, 
wrinkled,  brown  or  pink  membrane  is  formed.  This  mem- 
brane is  detached  easily  (Fig.  49).     A  culture  of  the  potato 


BA  CILL  US  MYCOIDES.  143 

bacillus  is  obtained  by  exposing  to  the  air  for  a  few  minutes 
a  Petri  dish  containing  a  slice  of  sterile  potato. 

Bacillus  prodigiosus :  This  germ  is  so  short  as  frequently  to 
be  mistaken  for  a  coccus  (Fig.  52).  It  is  found  in  the  air, 
water,  milk,  on  bread,  potatoes,  and  meat,  and  at  times  in  the 
axillsp.  It  is  the  cause  of  red  sweat.  It  has  flagella,  but  is 
only  slightly  motile.  It  does  not  sporulate,  and  liquefies  gela- 
tin very  rapidly.  It  is  a  facultative  anaerobe,  and  grows 
quite  rapidly  at  the  room  temperature  on  all  ordinary  media 
(Fig.  51).  It  is  stained  with  the  anilin  dyes,  but  not  with 
Gram's  stain. 

When  grown  in  the  presence  of  oxygen,  it  develops  a 
beautiful  deep-red  or  carmine  color,  especially  upon    potato 

Fig.  51.  Fig.  52. 


Bacillus  prodigiosus. 

and  agar-agar,  without  discoloring  the  media.  A  trimethyl- 
amin  odor  is  given  off  from  all  the  cultures.  The  pigment 
is  used  commercially  to  some  extent. 

,  Bacillus  violaceus :  This  is  a  very  small,  slender  rod,  with 
rounded  ends,  and  containing  a  central  spore.  It  is  found  in 
water.  It  possesses  .only  a  few  terminal  flagella,  but  is 
actively  motile.  It  is  a  facultative  anaerobe,  growing  at  the 
room  temperature  on  all  the  ordinary  culture-media. 

Gelatin  is  liquefied  very  rapidly  without  peculiar  charac- 
teristics. .  In  the  presence  of  oxygen  it  produces  a  beautiful 
permanent  indigo-blue  pigment,  which  may  be  so  intense  as  to 
appear  black.  It  coagulates  milk  and  stains  with  the  anilin 
dyes.     Gram's  stain  is  not  applicable. 

d     Bacillus  mycoides:  Known  also  as  Bacillus  ramosus,  the 


144 


NON-PATHOGENIC  BACTERIA. 


root  or  "  wurzel "  bacillus.  It  is  found  in  water  and  in 
the  upper  layers  of  the  soil.  It  is  a  large,  thick  bacillus, 
with  rounded  ends,  not  flagellated  and  but  slightly  motile. 
It  frequently,  in  culture,  forms  long  chains  or  threads,  and 
usually  contains  a  central  spore.  It  is  a  facultative  anaerobe, 
with  strong  aerobic  tendencies,  growing  rapidly  at  the  room 
temperature  with  liquefaction  of  the  gelatin.  It  is  stained 
with  all  the  anilin  dyes,  including  Gram's. 

It  forms  a  thin  whitish  growth,  con- 
sisting of  a  very  dense  network  of  fine 
freely  interlacing  threads.  The  growth 
resembles  the  gnarled  roots  of  an  old  tree 
radiating  from  a  common  centre,  from 
which  it  derives  its  name  of  root  bacillus 
(Figs.  53  and  54).  The  growth  on  agar 
is  very  characteristic. 

Fig.  54. 


Fig.  53. 


Bacillus  mycoidos. 

Bacillus  fluorescens  liquefaciens :  Found  in  water  and 
putrefying  liquids;  occasionally  in  the  conjunctival  sac.  It 
is  a  very  small  actively  motile  rod,  containing  no  spores.  It 
has  numerous  flagella.  It  is  strongly  aerobic,  and  grows 
rapidly  on  all  ordinary  media  at  the  room  temperature  with 
liquefaction  of  the  gelatin.  It  is  easily  stained  with  the 
ordinary  dyes.  It  forms  a  fluorescent,  greenish-yellow  pig- 
ment on  all  media  except  the  potato,  on  which  the  growth  is 


MICROCOCCUS  AGILIS  OF  ALI-COHEN. 


145 


brownish.     A  similar  organism  is  found  in  water,  but  it  does 
not  liquefy  gelatin. 

Bacillus  acidi  lactici :  Found  in  sour  milk.  It  is  a  short, 
thick  rod,  usually  occurring  in  pairs  ;  non-motile,  with  large 
shining  spores.  It  has  no  flagella.  It  is  a  facultative 
anaerobe,  and  grows  on  all  the  usual  media  without  liquefy- 
ing the  gelatin.  When  grown  in  milk,  it  breaks  up  the  milk- 
sugar  and  forms  lactic  acid  and  gases,  with  precipitation  of 
the  casein.  It  stains  readily  with  the  anilin  dyes.  Its  tem- 
perature optimum  is  about  20°  C.  On  gelatin  it  forms  a 
thick,  dry,  whitish  crust.     It  diifers  from  the  Bacterium  acidi 


Fig.  55. 


Fig.  56. 


Bacterium  acidi  lactici. 


lactici  (Figs.  55  and  56)  in  that  it  does  not  produce  alcohol 
in  milk. 

Bacillus  butyricus  :  This  organism  is  found  also  in  milk, 
and  is  the  cause  of  butyric  acid  fermentation.  It  is  a  very 
slender  rod,  of  varying  length,  with  rounded  ends  and  a  large 
central  spore.  It  is  flagellated  and  very  motile.  It  is 
strongly  aerobic,  and  grows  best  at  the  temperature  of  the 
body.  Gelatin  is  rapidly  liquefied.  The  casein  of  milk  is 
coagulated  and  decomposed,  with  butyric  acid  fermentation. 
On  gelatin  it  forms  a  very  delicate,  yellowish  surface  covering 
which  is  quite  characteristic.  It  is  stained  easily  with  the 
usual  dyes. 

Micrococcus  agilis  of  Ali-Cohen  :  This  organism  can  be  culti- 
vated from  drinking-water,  and  is  the  only  flagellated,  motile 

10— Bact. 


146  NON-PATHOGENIC  BACTERIA. 

coccus.  It  possesses  a  single  flagellura.  It  is  a  facultative 
anaerobe,  growing  very  readily  on  all  ordinary  media  at  the 
room  temperature.  It  produces  a  rose-red  pigment.  Gelatin 
is  slowly  liquefied.  The  coccus  stains  with  the  anilin  colors 
and  with  Gram\s  stain. 

Micrococcus  urese :  Usually  this  is  found  only  in  urine 
which  has  undergone  ammoniacal  decomposition  ;  but  occa- 
sionally it  can  be  cultivated  from  the  air.  It  grows  in  vary- 
ing forms,  sometimes  as  a  micrococcus,  and  at  other  times  as 
a  diplococcus  or  streptococcus.  It  is  strongly  aerobic,  grow- 
ing best  at  a  temperature  near  that  of  the  body.  Gelatin  is 
not  liquefied.  It  decomposes  urea,  producing  ammonium  car- 
bonate. It  is  stained  easily  by  the  anilin  dyes,  but  not  with 
Gram's.  A  Bacterium  ureoe  also  is  described,  with  properties 
similar  to  those  of  the  micrococcus.  It  is  probably  only  a 
variation  of  the  latter.  The  tube  cultures  of  the  coccus  are 
not  characteristic.  In  plate  culture  waxy-looking  colonies 
are  formed. 

Sarcina  ventriculi :  Several  different  species  of  sarcina  have 
been  described,  of  which  this  is  the  most  important.  It 
is  found  in  the  stomach  of  man  and  animals  under  normal 
conditions.  During  fermentative  processes,  and  especially  in 
dilatation  of  the  stomach,  the  sarcin^e  are  present  in  excess. 

It  is  a  facultative  aerobe,  growing  with  moderate  rapidity 
and  without  liquefaction  of  the  gelatin.  The  growth  is  usually 
colorless,  but  in  time  becomes  slightly  yellowish. 

Sarcina  pulmonum  is  found  in  the  air-passages.  Sarcina 
lutea,  S.  aurantiea,  etc.,  are  found  in  the  air,  and  are  color- 
producing.  In  every  other  respect  they  resemble  Sarcina 
ventriculi. 

The  Oppler-Boas  bacillus  is  found  in  the  stomach  of  per- 
sons suffering  with  gastric  carcinoma,  and  in  diseases  in  w^hich 
the  conditions  in  the  stomach  are  the  same  as  in  carcinoma. 
It  is  not  distinctive  of  gastric  carcinoma.  It  has  never  been 
cultivated. 

Spirillum  rubrum:  This  organism  is  of  absolutely  no  clini- 
cal importance,  but  serves  as  an  examjile  of  the  spirillum 
class.  Esmarch  found  it  in  the  body  of  a  mouse  dead  of 
septicaemia.     It  varies  considerably  in  length,  is  very  motile, 


LEPTOTHRIX  EPIDERMIDIS. 


147 


flagellated  at  both  ends,  and  does  not  form  spores  (Figs.  57 
and  58).  It  is  a  facultative  anaerobe,  growing  best  at  the 
temperature  of  the  body.  It  does  not  liquefy  gelatin.  In 
cultures  it  frequently  forms  long  spirals.  When  grown  in 
the  presence  of  oxygen,  the  color  of  the  growth  is  white.     In 


FiQ.  57. 


Fig.  58. 


Spirillum  rubrum. 


It 


the  absence  of  oxygen  a  wine-red  pigment  is  produced 
is  stained  readily  with  the  a  nil  in  dyes. 

Spirillum  denticolum :  This  organism  is  found  at  the  gin- 
gival junction  of  teeth  covered  with  salivary  calculi.  It 
forms  very  long  spirals,  and  is  therefore  frequently  classed  as 
a  splrochcete.  It  is  very  slender  and  irregular.  It  has  not 
been  cultivated. 

Leptothrix  buccalis :  Although  usually  this  organism  is 
classed  as  a  non-pathogenic  bacterium,  it  is  perhaps  not  such 
in  the  strict  sense  of  the  word,  because  it  is  responsible  for  a 
disease, — caries  of  the  teeth.  Miller  was  the  first  to  describe 
it  accurately,  and  it  is  known  also  as  Miller^s  leptothrix.  It 
is  a  very  slender,  long,  and  much  twisted  organism,  of 
extremely  variable  form.  It  has  not  been  cultivated.  Some 
varieties  give  the  iodine  reaction.  Occasionally  it  is  possible 
to  demonstrate  segments,  but  they  are  at  no  time  very  dis- 
tinct. 

Leptothrix  epidermidis  :  This  has  been  found  on  the  healthy 
skin.  It  consists  of  thick,  freely  interwoven,  unbranching, 
jointed  threads.  It  is  distinctly  motile,  but  flagella  have  not 
yet  been  demonstrated.  It  stains  with  the  anil  in  dyes  and 
Gram's  stain.     It  is  a  facultative  anaerobe,  growing  luxuri- 


148  NON-PATHOGENIC  BACTERIA. 

antly  at  either  the  incubator  or  room  temperature.  Gelatin 
is  liquefied  rapidly.  The  growth  on  gelatin  or  agar  is  white 
or  creamy,  red  on  potato.     It  does  not  sporulate. 

Vibrio  berolinensis :  This  bacterium  is  found  in  water,  and 
because  of  its  resemblance  to  the  spirillum  of  Asiatic  cholera 
is  of  importance.  It  is  not  pathogenic  for  man,  but  guinea- 
pigs  succumb  rapidly  when  inoculated  with  pure  cultures. 
Its  morphology  is  exactly  like  that  of  the  cholera  germ,  but 
in  culture  tlie  difference  between  the  two  is  quite  apparent. 
It  gives  the  nitroso-indol  or  cholera-red  reaction  very  strongly. 

Several  other  non-poihogenic  organisms  resembling  the 
cholera  germ  are  found  in  water,  and  they  will  be  considered 
in  connection  with  that   organism. 

The  non-pathogenic  bacteria  which  bear  a  resemblance  to 
any  of  the  pathogenic  bacteria,  so  that  they  may  be  mistaken 
for  them,  will  be  described  together  with  such  organisms,  so 
that  their  differentiation  will  be  understood  more  clearly. 


CHAPTER  II. 

MOULDS  ;  FILAMENTOUS  FUNGI ;   HYPHOMYCES. 

Besides  being  the  exciting  cause  of  some  diseases,  especi- 
ally those  of  the  skin,  moulds  are  frequently  met  in  the 
laboratory  in  the  way  of  culture  contaminations. 

Filamentous  fungi  is  an  infinitely  better  name  than  moulds  ; 
and  is  also,  in  a  measure,  descriptive  of  their  appearance  and 
method  of  reproduction.  Their  growths  are  often  very  beau- 
tiful, especially  when  pigments  are  formed.  A  filamentous 
fungus  consists  of  thread-like  cells  or  filaments  which  do  not 
contain  chlorophyl  and  which  have  an  apical  growth.  They 
interlace  very  freely  and  grow  luxuriantly,  often  forming 
dense,  heavy,  felt-like  membranes.  The  growth  is  usually 
very  dry,  but  occasionally  the  surface  of  the  membrane  is 
studded  with  minute  dew-drop-like  pearls ;  or  the  moisture 
may  be  diffused,  giving  the  growth  the  appearance  of  a  crust 
or  scutulum.  The  threads  forming  the  growth  are  termed 
hyphoe,  and  the  growing  or  vegetative  portion  of  the  fungus 
is  the  mycelium.  Arising  from  the  mycelium  is  the  fruit- 
bearer  or  sporangium.  This  carries  the  spores  or  conidia. 
From  the  spores  are  developed  new  hyphse  and  new  fungi. 

These  fungi  are  classified  according  to  the  structural  differ- 
ence in  the  sporangium.  Several  thousand  different  kinds 
of  moulds  have  been  described,  only  a  small  number  of 
which  possess  clinical  importance.  They  are  divided  also 
into  saprophytes  and  parasites.  The  majority  of  mould  fungi 
are  saprophytes,  and  are  not  met  with  in  man.  The  parasitic 
fungi  may  be  the  cause  of  disease  in  the  human  organism. 
This  parasitism  may  be  purely  accidental,  although  a  few 
fungi  are  really  obligative  parasites. 

Moulds  as  a  class  are  strict  aerobes,  and  require  an  acid 
medium  for  their  development.     That  is  one  reason  why  they 

149 


150     MOULDS;   FILAMPJNTOUS  FUNGI;  HYPHOMYCES. 

do  not  thrive  in  the  body.  The  absence  of  oxygen  and  the 
alkalinity  of  the  tissues  speedily  prove  fatal. 

Those  that  survive  may  become  pathogenic  by  developing 
excessively,  and  thus  acting  as  a  foreign  body.  Levy  and 
Klemperer  say  that  there  is  no  actual  multiplication,  but 
simply  a  germination.  The  number  of  spores  injected  is  also 
of  importance,  as  many  disease  foci  are  required  to  produce 
actual  disease.  The  animal  dies  as  a  result  of  the  extension 
of  the  foci  of  disease,  and  not  from  intoxication.  Diseases 
of  the  surface  of  the  body  due  to  the  filamentous  fungi  are 
common,  but  rarely  prove  fatal. 

Moulds  are  distributed  widely  in  nature,  and  cultures  of 
all  varieties  are  obtained  readily.  The  principal  moulds  are 
the  following : 

Aspergillus  or  bulbous  moulds  (Fig.  59) :  The  sporangium 
terminates   in   a  club,  which  is  surrounded  and  completely 

Fig.  59.   . 


Aspergillus. 


At  b  a  few  of  the  spore-bearing  sterigmata  are  shown ;  the  usual 
picture  is  given  at  a.    (Mez.) 


covered  by  short,  thick,  flask-shaped  structures  radially 
arranged.  These  are  known  as  sterigmata^  and  on  the  ends 
of  them  are  found  the  conidia  or  spores.  Aspergillus  fumi- 
gatus,  Aspergillus  glaucus,  and  Aspergillus  niger  are  examples 
of  this  class.     The  aspergillus  moulds,  especially  Aspergillus 


MUCORINI  OR   GLOBULAR  MOULDS.  151 

fumigatuHy  are  the  cause  of  most  of  the  so-called  mycoses, 
such  as  keratomycosis,  otomycosis,  myringomycosis,  and 
pneumonomycosis.  The  growth  is  either  black,  gray,  green, 
or  yellow  in  color. 

Penicillium  or  brush  moulds  (Fig.  60) :  In  this  variety  the 
terminal  extremity  of  the  sporangium  divides  dichotomously 
into  small  endings,  basidicij  which  form  a  brush.  On  the 
free  end  of  each  basidium  is  a  long  row  of  spores,  as  though 


Penicillium.    (Lehmann.) 

the  end  of  the  basidium  had  segmented  into  small  globules. 
PeniGillium  glaucum  is  the  example  of  this  class.  It  is  found 
widely  distributed  in  nature,  and  is  the  most  common  mould. 
Its  growth  on  bread  is  at  first  white,  but  as  soon  as  sporula- 
tion  occurs  it  assumes  a  greenish  color. 

Mucorini  or  globular  moulds:  These  moulds  (Fig.  61), 
although  very  common,  are  not  met  with  so  often  as  the  pre- 
ceding group.  Their  growth  is  white.  The  end  of  the 
sporangium  enlarges  to  form  a  globular  bulb,  which  is  parti- 
tioned off  into  several  compartments,  each  of  which  contains 


152     MOULDS;  FILAMENTOUS  FUNGI;  HYPHOMYCES. 

a  large  oval  spore.  The  bulb  is  enclosed  in  a  cap,  the  ealu- 
mella,  which  remains  open  when  the  spores  ripen  and  become 
scattered. 

Oidia  or  segmented  moulds :  The  structure  of  these  moulds 
is  very  simple.  They  represent  a  transition-stage  between 
the  moulds  and  the  yeasts.  At  times  they  are  typical  moulds, 
and  then  again  they  resemble  the  yeasts  in  structure.  The 
sporangium  is  very  indistinct  and  often  appears  to  be  absent. 
The  spores  are  formed  directly  from  the  sporangium  or  from 
the  mycelium   by  a  process  of  segmentation  similar  to  that 

Fig.  61. 


seen  in  the  penicillii. 
the  type  of  this  class. 
and  rancid  butter. 


Mucor  stolonifer.    (Mez.) 

O'idium  albicans  or  thrush  fungus  is 
O'idium  lactis  is  the  cause  of  sour  milk 


The  actinomyces  has  heretofore  been  considered  a  fungus, 
and  because  of  its  peculiar  appearance  was  called  the  ray 
fungus.  It  is  still  often  referred  to  as  the  streptothrix  mould 
or  fungus,  but  there  can  be  no  question  that  this  organism 
belongs  to  the  higher  bacteria,  and  not  to  the  moulds.  It  is 
really  a  transition-stage  between  the  filamentous  moulds  and 
the  bacteria  or  fission  fungi.      Hektoen  thoroughly  investi- 


MICROSPORON  FURFUR. 


153 


gated  this  organism  some  years  ago,  and  found  that  in  culture 
it  very  closely  resembled  the  tubercle  bacillus.  Since  then 
many  bacteriologists  look  upon  these  two  varieties  and  also 
the  glanders  bacillus  as  streptothrixes  or  mycobacteria. 
Other  members  of  this  group  are  Streptothrix  madurcBj  Strep- 
tothrix  farcincey  Streptothrix  Fcersteriy  and  Streptothrix  pseudo- 
tuberculosa. 

Fig.  62. 


AcJiorion  Schoerdeinii.     (After  Kaposi.) 

Moulds  which  closely  resemble  the  mucorini  are  the  Ach- 
orion  Schoenleinii  (Fig.  62),  the  cause  of  favus ;  Tricophyton 

Fig.  63. 


Trichophyton  tonsurans.    Diagrammatic.    (Lehmann.) 

tonsurans  (Fig.  63),  the  cause  of  herpes  tonsurans ;  and  Micro- 
sporon  furfur  (Fig.  64),  the  cause  of  pityriasis  versicolor. 
The  filamentous  fungi  are  examined  best  in  an  unstained 


154     MOULDS;  FILAMENTOUS  FUNGI;  HYPHOMYCES. 

condition,  as  they  do  not  take  stains  well.  A  small  portion 
of  the  mould  colony  is  rubbed  up  gently  with  50  per  cent, 
alcohol  containing  a  few  drops  of  ammonia,  and  then  mounted 
in  glycerin.     The  cover-glass  is  rimmed  with  Tarrant's  balsam 

Fig.  64. 


Microsporon  furfv/r.    (After  Kaposi.) 

or  sealing-wax.     A  permanent  preparation  may  also  be  made 
in  Unna^s  solution : 


Gelatin, 

1  part ; 

Alcohol, 

25  parts ; 

Solution  of  ammonia, 

25     '^ 

Glycerin, 

25     " 

Water, 

35     " 

Unna  recommends  that  the  cover-slip  preparation  be  placed 
in  5  per  cent,  potassium  hydroxide  for  one  minute,  rinsed  in 


CULTIVATION  OF  MOULDS.  155 

water  for  five  minutes,  and  then  placed  in  a  5  per  cent,  acetic 
acid  solution  for  a  few  minutes.  They  are  stained  with  a 
strong  anilin  gentian-violet  stain.  The  staining  is  greatly 
facilitated  if  the  stain  or  the  preparation  covered  with  stain 
is  heated  gently. 

Moulds  are  cultivated  just  like  the  bacteria,  except  that  the 
medium  must  have  an  acid  reaction.  Bread-pap  is  a  most 
useful  culture-medium,  and  is  used  very  widely  for  this  pur- 
pose. The  aspergillus  will  outgrow  any  of  the  other  moulds, 
and  in  order  to  get  a  pure  culture  of  any  one  mould  it  will 
be  necessary  to  inoculate  an  animal  by  injecting  the  mould 
in  water  into  the  abdominal  cavity.  The  different  varieties 
will  separate  and  form  colonies  as  the  bacteria  do  on  a  plate 
or  Petri  dish  culture.  There  is  no  necessity,  however,  for 
making  pure  cultures  of  the  filamentous  fungi,  as  they  can 
be  studied  in  a  mixed  culture  just  as  well. 


CHAPTEE  III. 

YEASTS;   BUDDING  FUNGI;   SACCHAROMYCES. 

The  yeasts  are  known  also  as  the  blastomyces  group  of 
fungi.  They,  like  the  bacteria,  contain  no  chlorophyll.  The 
yeast-cells  are  slightly  round,  and  multiply  by  budding  like 
a  tuber  on  a  potato.  They  are  the  cause  of  alcoholic  fermen- 
tation in  sugar.  The  bud  looks  like  a  small  sprout,  and  is 
detached  finally  from  the  parent  cell  to  take  on  the  functions 

Fig.  65. 


a 

a.  Saccharomyces.    b.  Cell  with  four  spores.    (Lehmann.) 

of  a  matured  cell  (Figs.  65  and  66).  Under  certain  condi- 
tions some  of  the  yeasts  may  form  hyphse  and  mycelia.  This 
usually  occurs  when  the  medium  has  an  alkaline  reaction  or 
when  it  is  deficient  in  sugar.  The  yeasts  grow  best  at  the 
room  temperature  and  in  the  presence  of  oxygen.  In  fact, 
most  of  the  budding  fungi  are  strongly  aerobic.  The  culture- 
medium  must  contain  sufficient  organic  matter  and  must  have 

... 
an  acid  reaction.     Putrefaction  inhibits  their  growth.     They 

are  cultivated  like  the  mould  fungi.  They  can  be  examined 
in  water  or  bouillon,  or  mounted  in  glycerin. 

The  most  common  and  best  known  yeast  is  Saccharomyces 

156 


PATHOGENIC  YEASTS.  157 

cerevisiae  or  beer  yeast  This  variety  has  been  found  in  the 
coating  of  the  tongue,  in  vomited  matter,  in  diarrhoeal  stools, 
in  the  vagina,  and  in  diabetic  urine.  There  are  said  to  be 
several  varieties  of  the  cerevisise,  each  of  which  gives  the 
malt   product  a  characteristic  taste.     Brewers  cultivate  the 

Fig.  66. 


Saccharomyces  albicans.    (Grawitz.) 

yeasts  with  this  end  in  view,  and  the  different  kinds  of  beer 
are  produced  in  this  way. 

The  yeast  which  forms  the  mouldy  growth  on  wine-pre- 
serves, and  sour  kraut  is  the  Mycoderma  vini  or  Saccharomyces 
mycodej'ma.     Several  of  the  yeasts  produce  pigments. 

Prominent  among  the  pathogenic  yeasts  are  Saccharo- 
myces hominis,  which  was  found  in  a  case  of  pyaemia ;  and 
Saccharomyces  subcutaneus  tumefaciens,  found  in  a  large  myxo- 
matous tumor  of  the  thigh. 

Yeasts  have  been  observed  in  the  blood,  sputum,  and  urine 


158        YEASTS;  BUDDING  FUNGI;  SACCHAROMYCES. 

of  a  typhus  patient ;  in  pus  from  a  case  of  otitis  media  ;  in  the 
pseudomembranous  angina  occurring  in  a  typhoid  patient. 

According  to  Demme,  Saccharomyces  ruber,  occurring  on 
red  raspberries,  was  the  cause  of  a  severe  epidemic  of  intes- 
tinal catarrh. 

Busse,  in  1 895,  found  a  pathogenic  blastomyces  in  a  large 
swelling  of  the  tibia,  which  on  microscopic  examination 
showed  a  sarcomatous  structure.  The  fungus  was  obtained 
from  the  tumor  and  isolated  in  culture.  The  blastomyces 
nodules  resemble  sarcomatous  growths  very  closely. 

The  yeast-cell  may  be  mistaken  for  a  tumor-cell  inclusion, 
which  is  seen  so  frequently  in  malignant  growths.  This  find- 
ing is  the  reason  for  the  belief  that  the  blastomyces  is  the 
cause  of  malignant  growths.  The  conclusions  arrived  at  are 
based  on  a  series  of  experiments  conducted  by  several  promi- 
nent pathologists,  but  a  careful  and  unbiased  analysis  of 
their  results  forces  us  to  the  conclusion  that  the  occurrence 
of  yeasts  in  malignant  growths  is  purely  incidental  and  acci- 
dental, and  should  not  be  looked  upon  as  an  etiologic  factor  or 
even  as  a  contributing  cause. 

Gilchrist,  in  1884,  and  other  investigators  later,  found  the 
blastomyces  or  yeast  fungus  in  certain  peculiar  skin  affections. 
The  pathology  was  that  of  scrofuloderma,  a  chronic  diffuse 
inflammation.  The  yeast  fungus  was  obtained  in  each  case 
and  cultivated.  The  disease  is  known  as  cutaneous  blasto- 
mycosis or  blastomycetic  dermatitis.  AVe  mention  these  facts 
in  order  to  impress  the  reader  with  the  importance,  clinically, 
of  the  yeast  fungi,  and  to  encourage  research  work  in  this 
direction. 


PLATE  11. 


FIG.  1. 


Section  through,  wall  of  abscess,   showing  staphylococcus 
pyogenes  aureus.    (Baumgarten.) 


FIG.  2. 


A..   ,■■■  -^'i;^v\C.:-VvXv. 


--■w^:<'-;5r 


Streptococcus  pyogenes.    Streptoeoecus  erysipelatis.    (Prudden.) 


PART  III. 

PATHOGENIC   BACTERIA. 


CHAPTER  I. 

SUPPURATION— PUS   COCCI. 

Suppuration,  or  the  formation  of  pus,  is  not  necessarily  the 
result  of  bacterial  activity.  It  may  represent  tissue-reaction 
to  irritants  other  than  bacteria,  or  to  both  combined.  When 
suppuration  is  due  to  micro-organisms,  it  is  called  a  specific 
process ;  when  due  to  other  agents,  it  is  called  a  non-specific 
process.  Turpentine,  croton  oil,  carbolic  acid,  ammonia,  and 
very  strong  solutions  of  mercuric  chloride  cause  pus-formation. 
Identical  results  can  also  be  produced  by  injecting  cultures 
of  the  pus-forming  bacteria  that  have  been  sterilized  for  two 
hours  or  more ;  by  injecting  sterilized  products  of  bacterial 
activity,  such  as  the  albunioses,  enzymes,  etc.  Some  of 
the  vegetable  alkaloids,  and  any  chemical  substance  which 
exerts  a  chemotactic  action  on  the  leucocytes  or  which  induces 
necrosis  of  tissue,  will  cause  a  typical  suppuration.  No 
matter  whether  the  pus  is  the  result  of  the  action  of  bacteria 
or  chemicals,  the  composition  of  the  pus  is  the  same,  except 
that  non-specific  pus  does  not  contain  bacteria  and  is  not 
infectious. 

Before  the  nature  of  bacteria  and  their  part  in  the  produc- 
tion of  disease  were  thoroughly  understood,  pus-formation 
was  looked  upon  as  a  necessary  step  in  the  healing  of  wounds 
and  in  the  resolution  of  the  infectious  diseases.  The  physi- 
cian did  all  in  his  power  to  facilitate  the  occurrence  of  sup- 
puration, and  to  have  as  much  pus  as  possible,  so  as  to  hasten 

159 


160  SUPPURATION- PUS  COCCI. 

healing  or  recovery.  Pus  was  taken  to  be  significant  of  the 
discharge  of  the  poison  which  was  responsible  for  the  infec- 
tion, and  the  sooner  this  poison  was  gotten  rid  of  the  better. 
The  wound  could  not  |ieal  until  suppuration  had  occurred. 
In  lobar  pneumonia  pus  in  the  sputum  was  anxiously  looked 
for,  and  its  appearance  hailed  with  delight.  The  advent  of 
antisepsis  completely  revolutionized  the  treatment  of  wounds, 
and  the  physician  -HoVVk)«^\a^|  in  Ijjs  power  to  prevent  sup- 
puration. The  occurrence  of  silpphration  is  considered  a 
mark  of  inefficiency  on  the  part  of  the  attendant,  and  is 
known  to  interfere  with  and  even  prevent  the  healing  of 
wounds.  All  the  surgeon's  efforts  are  directed  toward  the 
prevention  of  sepsis.  Sterilization  and  disinfection  are  car- 
ried out  so  carefully  and  thoroughly  that  pus-formation  or 
infection  with  the  pus  bacteria  is  a  rather  infrequent  occur- 
rence. 

Many  bacteria  are  responsible  for  the  formation  of  pus,  but 
those  which  are  classed  particularly  as  the  pus-producing  organ- 
isms, and  which  do  not  necessarily  produce  any  general  in- 
fectious disease,  but  only  localized  suppurations,  are  : 

The  pus  cocci — the  staphylococci  and  streptococci ; 

Bacillus  pyocyaneus  ;  blue-pus  bacillus ; 

Micrococcus  gonorrhoeae,  or  gonococcus  ; 

Diplococcus  pneumoniae,  or  pneumococcus  ; 

Bacillus  of  Friedlaender,  or  pneumobacillus; 

Diplococcus  intracellularis  meningitidis  ;  meningococcus. 
Other    bacteria   which    have   been   found   in   suppurative 
lesions  are  Bacillus  typhosus,  Bacilhis  coll  communis,  and  the 
various  organisms  belonging  to  the  so-called  "  colon  group.'' 

Staphylococcus  Pyogenes. 

The  pyogenic  staphylococci  are  divided  into  several  kinds 
depending  upon  their  color-production.  We  have  Staphylo- 
coccus pyogenes  aureus,  Staphylococcus  pyogenes  albus,  Sta- 
phylococcus pyogenes  citreus.  Staphylococcus  cereus  albus,  and 
Staphylococcus  cereus  flavus. 

Habitat :  The  staphylococci  are  widely  distributed  in 
nature,   but  are  never  found  in  very  large  numbers  in  any 


STAPHYLOCOCCUS  PYOGENES. 


161 


one  locality.  With  but  few  exceptions  they  are  always  para- 
sitic. They  are  always  found  on  the  surface  of  the  body,  in 
the  mouth,  nose,  eyes,  and  ears,  beneath  the  finger-nails,  in 
the  saliva,  and  occasionally  in  the  feces ;  in  the  dust  of  the 
street,  on  the  floors  and  Avails  of  houses  and  hospitals,  and 
wherever  they  may  have  been  deposited  from  a  previous 
infection.  Occasionally  they  are  found  in  the  air  and  in  water. 
Biology  and  morphology :  The  staphylococci  are  from  0.7  ju 
to  1.2  fi  in  diameter,  and  have  an  arrangement  resembling  a 
bunch  of  grapes  (staphylos),  from  which  they  derive  their 
name.     The  typical  grouping  is  seen  only  in   preparations 


Fig.  67. 


<^^ 


staphylococcus  pyogenes.    (Park.) 


made  directly  from  pus  (Fig.  67).  In  culture  specimens  the 
staphylococcus  occurs  usually  as  a  simple  micrococcus,  some- 
times in  masses,  and  sometimes  as  a  typical  staphylococcus. 
Staphylococci  are  not  motile,  and  have  no  flagella.  They 
divide  by  fission. 

The  entire  group  grows  very  readily  on  all  the  various 
culture-media,  and  equally  well  in  the  presence  or  absence  of 
oxygen,  but  pigment  is  formed  only  in  the  presence  of  oxygen. 
The  temperature  optimum  is  that  of  the  body,  37°  C. ;  but 
they  exhibit  some  growth  in  a  temperature  as  low  as  6°  C. 
and  as  high  as  44°  C.  They  are  stained  readily  with  all  the 
anilin  dyes,  and  also  by  Gram's  method. 

11— Bact. 


162  SUPPURATION— PUS  COCCI. 

On  gelatin  plates  small  round  granular  colonies,  with  a 
sharply  defined  border  and  a  whitish-gray  color,  are  seen  to 
develop  within  forty-eight  hours.  The  gelatin  is  gradually 
liquefied  around  these  colonies.  The  colony  is  high  in  the 
centre  and  gradually  slopes  down  toward  the  periphery.  It 
is  very  thin  at  the  edge.  It  resembles  a  small  pile  of  sand. 
After  a  few  days  the  golden-yellow  color  appears,  beginning 
at  the  centre  and  gradually  spreading  toward  the  periphery. 
The  color  is  not  so  pronounced  in  plate  colonies  as  in  tube 
cultures.  The  structure  of  these  colonies  is  studied  with  the 
low  power  of  the  microscope. 

On  agar-agar  jylates  the  appearance  of  the  colonies  is  simi- 
lar to  that  of  the  colonies  on  the  gelatin  plates,  but  there  is 
no  liquefaction  of  the  medium  and  the  pigment  is  more 
intense. 

In  the  gelatin  tube  culture  the  growth  occurs  along  the 
entire  length  of  the  stab,  with  rapid  liquefaction  of  the 
medium  in  the  form  of  an  inverted  cone.  The  culture  gradu- 
ally settles  to  the  bottom  of  this  cone,  where  pigment-forma- 
tion is  evident.  The  supernatant  liquid  is  always  cloudy  but 
not  colored.  Pigment-formation  is  not  well  marked  in  gel- 
atin tube  cultures. 

On  agar  stroke,  cultures  pigment-formation  appears  early 
and  is  very  intense,  beginning  at  the  centre  of  the  culture. 
The  growth  is  limited  to  the  needle  track,  and  is  very  heavy, 
moist,  and  shining,  with  well-marked  and  quite  regular 
edges.  At  first  the  growth  is  white,  but  in  a  few  days  the 
orange  pigment  begins  to  appear,  especially  if  the  tube  is 
kept  in  a  light  place,  with  a  plentiful  supply  of  oxygen. 

On  potato  the  growth  resembles  that  on  agar,  but  it  is  not 
limited  to  the  line  of  inoculation.  It  frequently  forms  a 
thick  moist  membrane  that  covers  the  entire  surface  of  the 
potato.     The  culture  gives  off  a  peculiar  sour  odor. 

Bouillon  rapidly  becomes  clouded,  but  without  the  produc- 
tion of  pigment. 

Milk  is  coagulated,  with  the  production  of  lactic  and  several 
other  acids. 

The  production  of  the  various  pigments  is  not  constant ; 
the  staphylococci  varying  in  this  respect.     The  cultures  may 


STAPHYLOCOCCUS  PYOGENES.  163 

remain  white,  or  when  transplanted  a  white  growth  may 
become  yellow. 

Vitality:  The  staphylococcus  is  an  exceedingly  tenacious 
germ,  retaining  its  vitality  for  a  long  time  under  the  most 
adverse  circumstances.  It  is  rapidly  killed  by  exposure  to 
live  or  streaming  steam  and  by  a  3  per  cent,  solution  of  car- 
bolic acid.  Sutures  contaminated  by  the  staphylococcus  are 
sterilized  in  one  minute  by  a  3  per  cent,  solution  of  formal- 
dehyde. 

Pathogenesis :  All  the  staphylococci  cause  local  suppurative 
inflammations,  and  exhibit  but  little  tendency  to  spread. 
Occasionally  they  are  the  cause  of  fatal  septicaemia  or  pyaemia, 
especially  when  they  find  their  way  directly  into  the  blood  or 
lymph-current,  or  when  the  process  is  very  virulent  and 
accompanied  by  rapid  absorption  of  the  poisonous  products 
of  the  germs. 

These  cocci  usually  gain  entrance  into  the  body  through  an 
abrasion  of  the  skin  or  mucous  membranes.  Infection  of 
the  ducts  of  the  glands  in  the  skin  results  in  the  formation 
of  a  cai^hunde  or  a^  furuncle.  It  is  said  that  infection  cannot 
occur  unless  the  skin  is  broken,  and  yet  infection  may  occur 
through  an  unbroken  mucous  surface,  as  in  staphylococcus 
sore  throat.  Staphylococcus  infection  is  not  a  very  serious 
aifair,  because  of  the  tendency  of  the  process  to  remain 
localized. 

The  staphylococci  are  found  in  all  abscesses  (except  in  cold 
abscesses,  which  are  sterile)  and  phlegmons,  impetigo,  ecthyma, 
acute  suppurative  inflammations  of  the  nose,  throat,  and 
mouth,  empyema,  tonsillar  abscess,  phlyctenular  conjunctivi- 
tis, suppurative  inflammations  of  the  middle  ear,  pelvic 
abscess,  and  generally  in  all  those  conditions  that  are  described 
as  localized  suppurations,  and  in  the  mixed  infections. 

Staphylococcus  pyogenes  aureus :  This  is  the  most  common 
and  also  the  most  virulent  of  the  staphylococci.  It  is  con- 
sidered the  type  of  the  group.  It  is  also  called  the  golden 
coccus,  because  of  the  beautiful  golden  or  orange  pigment 
which  it  produces  in  culture.  It  is  always  found  in  the  pus 
of  acute  abscesses. 

Staphylococcus  pyogenes  albus  :  So  far  as  its  appearance  and 


164  SUPPURATION—PUS  COCCI. 

growth  are  concerned,  this  germ  is  exactly  like  the  staphylo- 
coccus aureus,  except  that  it  does  not  produce  pigment.  Its 
growth  is  always  whitish.  It  is  found  everywhere,  but  pos- 
sesses little  virulence.  It  is  usually  the  cause  of  long-stand- 
ing suppurations,  such  as  the  suppuration  occurring  in  a 
fistulous  tract  or  a  chronic  otitis  media.  Welch  described  a 
somewhat  similar  organism,  which  he  called  the  Stcvphylo- 
coceus  epidermidis  albus.  It  is  constantly  found  both  on  the 
skin  and  in  its  deeper  layers.  He  believes  it  to  be  an  attenu- 
ated form  of  the  Staphylococcus  pyogenes  albus. 

Staphylococcus  pyogenes  citreus  :  This  organism  is  also  iden- 
tical with  the  staphylococcus  aureus,  but  in  culture  produces 
a  lemon-yellow  pigment.  It  is  very  uncommon,  and  is  always 
associated  with  the  other  varieties  of  staphylococci. 

Pathogenesis :  These  three  varieties  of  staphylococci  are 
always  associated.  In  very  acute  suppurations  the  yellow 
coccus  predominates ;  and  in  chronic  suppurations  the  albus 
predominates.  The  citreus  holds  the  middle  ground.  It  is 
not  so  common  as  either  of  the  other  two.  It  is  less  patho- 
genic than  the  aureus,  but  more  so  than  the  albus. 

Staphylococcus  cereus  albus  and  flavus  :  These  two  varieties 
are  very  uncommon.  They  have  been  found  on  the  skin  and 
in  the  external  auditory  canal.  They  do  not  liquefy  gelatin 
and  are  very  feebly  pathogenic.  They  resemble  the  other 
varieties  of  staphylococci  both  in  appearance  and  culture,  but 
do  not  liquefy  gelatin.  The  first  named  produces  a  waxy 
white  growth  and  the  other  a  waxy  yellow  growth. 

Streptococcus  Pyogenes. 

Biology  and  morphology :  This  organism  is  identical  with 
the  ^Streptococcus  erydpelatis  of  Fehleisen,  which  was  at  one 
time  considered  a  distinct  species.  It  is  from  0.4  /i  to  1  //.  in 
diameter,  and  always  forms  chains,  from  which  characteristic 
it  derived  its  name  of  the  "  chain  coccus  '^  (Figs.  68  and  69). 
These  chains  may  be  long  or  short,  and  a  streptococcus  longus 
and  hrevis  may  be  distinguished.  It  stains  well  with  the  anilin 
dyes  and  also  by  Gram's  method.  It  is  not  motile  and  has  no 
flagella.     Reproduction  takes  place "16y  fission.     Occasionally 


STREPTOCOCCUS  PYOGENES.  165 

some  of  the  individual  members  of  a  chain  are  larger  than 
the  others.  This  is  responsible  for  the  belief  that  possibly 
these  larger  cocci  are  arthrospores.  The  name  streptococcus 
conglomeratus  has  been  given  to  snarls  of  chains. 

Unlike  the  staphylococcus,  the  streptococcus  is  not  grown 
readily  in  culture.  That  is  accounted  for  by  the  fact  that  it 
is  an  exceedingly  virulent  germ,  possessing  but  little  vegeta- 
tive power.  In  order  to  preserve  the  culture,  frequent  trans- 
plantations are  made,  and  this  is  always  done  at  the  expense 
of  the  virulence  of  the  coccus.  It  becomes  considerably 
attenuated,  but  the  lost  virulence  can  be  regained  by  rapidly 

Fig.  68.  Fig.  69. 


streptococci  in  peritoneal   fluid,  partly     Streptococci  in  throat  exudate  smeared 
enclosed  in  leucocytes.  X  1000.  (Park.)  on  cover-glass.    X  1000.    (Park.) 

passing  the  coccus  through  rabbits  until  a  very  high  degree 
of  toxicity  is  obtained  (Fig.  70)..  Marmorek  says  that  the 
original  virulence  can  be  retained  if  a  culture-medium 
consisting  of  3  parts  of  human  blood-serum  and  1  part  of 
bouillon  is  used,  or  ass'  milk,  ascitic  fluid,  or  the  fluid  from  a 
pleural  eifusion.  The  virulence  of  individual  organisms  is 
apparently  subject  to  marked  variations.  The  requirements 
as  regards  temperature  are  the  same  as  those  of  the  staphy- 
lococcus.    It  is  a  facultative  anaerobe. 

On  gelatin  plates  ■tEe~stvepfxyGOCGim  forms  very  small,  finely 
granular,  translucent  colonies  of  a  very  light  color.     They 


166  SUPPURATION— PUS  COCCI. 

are  perfectly  flat,  round,  with  numerous  fine  projections  at 
the  periphery,  due  to  chains  of  cocci  which  reach  out  from 
the  colony  into  the  medium.  The  gelatin  is  not  liquefied. 
The  appearance  of  the  colony  under  the  microscope  is  quite 
characteristic. 

In  gelatin  tube  cultures  the  growth  is  formed  along  the  line 
of  inoculation.  It  is  very  slight,  and  consists  of  many  very 
small  distinct  spherical  colonies  that  resemble  the  colony  on 
the  plate.  They  never  become  confluent.  There  is  no  lique- 
faction of  the  media.     The  surface  growth  is  very  slight. 

In  agar-agar  strokes  a  very  similar  growth  develops  as  in 
the  gelatin,  but  not  so  rapidly,  and  the  colonies  are  almost 
translucent.     Sometimes  the  growth  is  so  slight  that  the  col- 

FiG.  70. 


streptococcus.    (Park.) 

onies  resemble  minute  drops  of  water.  The  growth  is  more 
rapid  on  glycerin-agar  than  on  ordinary  agar. 

On  potato  the  growth  is  almost  invisible. 

Bouillon  becomes  slightly  cloudy  and  contains  a  flocculent 
precipitate.  It  is  in  the  bouillon  cultures  that  the  variations 
in  the  formation  and  lengths  of  the  streptococcus  chains  are 
seen.     They  are  probably  only  cultural  characteristics. 

The  growth  on  blood-serum  is  almost  identical  with  that  on 
agar.     Jlilk  is  coagulated. 

Vitality :  An  exposure  of  ten  minutes  to  a  temperature  of 
52°  C.  kills  the  coccus.     It  is  more   resistant  to  chemicals. 


STREPTOCOCCUS  PYOGENES.  167 

A  1  :  2500  bichloride  solution  is  fatal  in  two  hours ;  1  :  300 
carbolic  acid,  in  two  hours;  1  :  50  peroxide  of  hydrogen,  in 
two  hours. 

Pathogenesis :  The  streptococcus  is  the  cause  of  all  severe 
and  rapidly  fatal  inflammations,  especially  those  of  the  lym- 
phatic system,  the  so-called  ''  spreading  "  inflammations.  The 
germ  has  been  found  in  hospital  wards  and  in  operating- 
rooms,  in  the  mouth,  nose,  pharynx,  intestinal  canal,  vagina, 
on  the  skin,  and  in  the  lesions  caused  by  it.  Infection  occurs 
in  the  same  manner  as  with  the  staphylococcus. 

The  streptococcus  pyogenes  is  the  specific  cause  of  erysip- 
elas (St.  Anthony^s  fire),  an  acute  inflammation  involving 
especially  the  subcutaneous  tissues,  and  it  is  always  found  in 
the  erysipelatous  patch,  particularly  at  its  periphery.  It 
occupies  the  lymph-spaces  and  lymph-vessels  of  the  skin,  and 
subcutaneous  tissues,  in  great  numbers.  The  streptococcus 
found  in  erysipelas  was  formerly  known  as  the  streptococcus 
erysipelatis  of  Fehleisen  ;  the  term  has  been  abandoned,  as  it 
is  no  longer  recognized  as  a  variety  of  streptococcus. 

It  is  always  found  on  the  heart  valves  in  ulcerative  endo- 
carditis ;  and  sometimes  in  the  blood  in  pneumonia,  otitis 
media,  meningitis,  phlegmons,  and  the  secondary  infection  in 
pulmonary  tuberculosis. 

It  is  always  present  in  the  uterus  in  puerperal  fever,  of 
which  it  has  been  said  by  some  to  be  the  specific  cause. 
Puerperal  fever  is  so  extremely  liable  to  follow  infection  with 
the  streptococcus  that  physicians  who  have  a  '^  pus  case " 
under  their  care,  or  any  streptococcus  infection,  always  refuse 
to  take  charge  of  obstetric  cases  during  that  time. 

It  is  found  very  commonly  in  the  diphtheritic  membranes 
in  the  throat,  and  in  non-diphtheritic  angina,  especially  that 
of  scarlet  fever ;  in  the  blood  of  scarlet  fever  patients,  and  in 
the  suppurative  sequelse  of  scarlet  fever. 

The  streptococcus  can  always  be  obtained  in  pure  cultures 
from  the  bleb  or  blister  over  an  erysipelatous  patch ;  or  by 
introducing  a  fine  needle  into  the  subcutaneous  tissues  and 
withdrawing  a  small  quantity  of  serum. 

Serum  :  Marmorek  has  succeeded  in  obtaining  an  anti- 
streptococcus  serum  which  possesses  a  decided  specific  action 


168  SUPPURATION— PUS  COCCI. 

on  all  streptococcus  infections.  The  serum  is  prepared  by 
immunizing  an  animal  to  live  cultures  of  a  very  virulent 
streptococcus.  The  streptococcus  toxin  is  a  diastase  which 
is  destroyed  when  it  is  exposed  to  a  temperature  of  70°  C. 
Although  all  the  streptococci  are  believed  to  be  of  one 
common  species,  the  antistreptococcus  serum  apparently  pos- 
sesses bactericidal  properties  only  for  the  streptococcus  from 
which  it  is  prepared.  Many  observers  are  of  the  opinion, 
however,  that  the  serum  of  any  one  streptococcus  antagonizes 
all  streptococci  more  or  less.  The  serum  should  always  l)e 
kept  in  a  c^ool  dark  place,  as  it  deteriorates  very  rapidly. 

Marmorek's  observations  have  been  confirmed  by  many 
reliable  investigators.  The  serum  has  been  iised  in  scarlet 
fever,  erysipelas,  puerperal  fever,  tonsillitis,  post-operative 
septicaemia,  phthisis,  and  bronchopneumonia,  with  very  grati- 
fying results.  It  should  be  used  only  in  suitable  cases,  and 
the  serum  must  be  fresh.  A  serum  which  is  more  than  six 
weeks  old  should  not  be  used,  as  it  is  practically  inert  after 
that  time. 

The  daily  dose  varies  with  the  severity  of  the  condition. 
Ordinarily  from  20  to  50  c.c.  of  the  standardized  serum  can 
be  used  daily  without  exhibiting  ill  effects. 

Some  very  excellent  results  have  been  obtained  with  Mar- 
morek's serum  in  streptococcus  pneumonias.  It  is  practically 
devoid  of  eflPect  in  the  pure  pneumococcus  pneumonia  or  in 
the  pneumonia  complicating  la  grippe  or  typhoid.  In  the 
stage  of  mixed  infection  in  phthisis^  the  ulcerative  stage,  this 
serum  can  be  used  with  benefit. 

It  may  be  of  interest  to  refer  briefly  at  this  time  to  Coley's 
serum.  It  was  noticed  by  a  number  of  clinicians  that  an 
accidental  infection  of  malignant  tumors  with  Streptococcus 
erysipelatis  was  in  some  instances  followed  by  a  complete  dis- 
appearance of  the  tumor.  Coley  verified  these  findings 
experimentally.  He  found  further  that  the  toxin  of  the 
streptococcus  was  preferable  to  the  living  culture.  Also,  that 
when  mixed  with  Bacillus  prodigiosus  the  efficiency  of  the 
serum  is  increased  considerably. 

Flasks  containing  slightly  acid  bouillon  are  inoculated  with 
a  virulent  culture  of  the  streptococcus  obtained  from  the  ery- 


BACILLUS  PYOCYANEUS.  169 

sipelas  lesion,  and  are  placed  in  the  incubator  for  three  weeks. 
The  same  flasks  are  then  inoculated  with  Bacillus  prodigiosus 
and  replaced  in  the  incubator  for  ten  or  twelve  days.  At  the 
end  of  this  time  the  flasks  are  well  skaken  and  their  contents 
poured  into  bottles  of  about  one-half  ounce  capacity.  These 
bottles  are  exposed  to  live  steam  for  one  hour.  The  toxin  is 
injected  directly  into  the  tumor  mass  or  into  its  periphery. 

The  best  results  from  the  use  of  this  combined  toxin  have 
accrued  in  the  treatment  of  accessible  sar-comata.  The  injec- 
tion is  followed  by  necrosis  and  a  gradual  disappearance  of 
the  tumor.  Quite  a  number  of  cases  have  been  successfully 
treated  in  this  manner.  The  serum  has,  however,  proved 
most  successful  in  the  hands  of  its  originator.  The  experi- 
ence of  the  vast  majority  of  the  profession  with  its  use  has 
not  warranted  its  continuance,  and  it  has  now  been  practically 
abandoned  except  by  a  few.  Its  use  is  restricted  largely  to 
inoperable  cases,  witli  the  hope  that  some  good  may  result. 

Bacillus  Pyocyaneus. 

Strictly  speaking,  this  is  not  a  pus-producing  germ,  but  it 
is  frequently  found  in  pus,  to  which  it  imparts  a  blue  or  green 
color.  For  this  reason  it  is  always  described  with  the  pus 
germs.  It  has  also  been  found  on  the  skin,  especially  in  the 
axillae,  in  the  external  auditory  canal,  and  in  the  intestinal 
mucus.  It  is  possible  that  very  large  numbers  of  the  organ- 
ism may  induce  suppuration. 

Biology  and  morphology  :  The  Bacillus  pyocyaneus  is  a  very 
small,  sjender,. and  exceedingly  motile  bacterium,  with  rounded 
ends7  and  possessing^  single  terminal  flagellum.  It  is  0.3 /i 
in  length  and  1.2//  in  width,  and  usually  occurs  singly, 
although  occasionally  it  forms  short  chains  of  four  or  five. 
It  does  not  sporulate,  reproducing  itself  by  fission.  It  is  a 
facultative  anaerobe,  although  developing  best  in  the  pres- 
ence of  oxygen.  The  anilin  dyes  stain  it  readily.  It  is 
decolorized  by  Gram's  stain.  Its  temperature  optimum  is 
indefinite,  as  it  grows  equally  well  at  either  the  room  or  body 
temperature  (Fig.  71). 

On  gelatin  plates  it  forms  small   flat  round  colonies  of  a 


170 


SUPPURATION— PUS  COCCI. 


slightly  greenish  color.  They  are  very  granular,  with  an 
jrregula^  border,  and  exhibit  some  radiatfon  like  a  strepto- 
coccus'colony.  The  gelatin  is  rapidly  liquefied^  the  colony 
sinking  into  the  mecliirm  as  liquefaction~progresses.  The 
colony  is  darker  at  its  centre  than  at  the  periphery. 

In  a  gelatin  stab  culture  the  growth  develops  rapidly  at  the 
surface  and  rather  slowly  along  the  line  of  the  needle  inocu- 
lation. The  medium  is  liquefied,  the  culture  settling  gradu- 
ally to  the  bottom.     The  liquefaction   is  not  characteristic. 

Fig.  71. 


Bacillus  pyocyaneus,  from  an  agar-agar  culture.    X  1000.    (Itzerott  and  Niemann.) 

The  liquefied  medium  may  be  colored  green  or  the  solid  por- 
tion blue,  or  the  blue  and  green  color  may  both  be  present  in 
the  same  culture. 

On  agar-agar  the  growth  develops  very  rapidly  along  the 
stroke.  The  growth  remains  white,  while  the  medium  is 
colored  green  because  of  the  formation  of  fluorescin,  a  soluble 
pigment.  If  the  medium  contains  an  excess  of  peptone,  the 
green  color  is  displaced  by  a  beautiful  deep  blue.  Bacillus 
pyocyaneus  forms  two  pigments,  ^Mo/Tsciw,  a  green  pigment, 
and  pyocyanin^  a  blue  pigment.     Pyocyanin  is  crystal! izable. 

The  growth  on  potato  is  very  luxuriant  and  of  a  brownish 


MICROCOCCUS  TETRAOENUS.  Ill 

color.     Milk  is  coagulated.     Bouillon  becomes  clouded  and  is 
colored  green. 

Pathogenesis :  In  man  the  organism  appears  to  be  purely 
saprophytic,  whereas  in  animals  it  is  intensely  pathogenic, 
especially  when  injected  into  the  subcutaneous  tissues.  It 
has  been  found  in  otitis  media,  pulmonary  tuberculosis,  peri- 
carditis with  eiFusion,  acute  angina,  meningitis,  bronchopneu- 
monia, dysentery,  diarrhoea,  etc. 

Micrococcus  Tetragenus. 

This  germ  belongs  to  the  same  class  as  Bacillus  pyocyaneus. 
It  is  usually  found  in  tubercular  septicaemia  in  association 
with  other  bacteria,  in  the  pus  of  empyema  subsequent  to 
pneumonia,  and  occasionally  in  the  saliva  of  healthy  persons. 

Biology  and  morphology  :  In  the  tissues  this  organism  occurs 
in  squares  of  four  cocci  (Fig.  72).     It  is  not  motile ;  does 

Fig.  72. 


Tetracoccus.    (Park.) 


not  sporulate;  has  no  flagella;  and  stains  readily  with  Gramas 
and  the  anilin  dyes.  It  grows  well  on  all  the  various  nutrient 
media  at  either  room  or  body  temperature.  It  is  a  faculta- 
tive aerobe.  It  measures  about  1  //  in  diameter,  and  is  fre- 
quently surrounded  by  a  gelatinous  capsule. 

In  blood  cultures  it  produces  minute  white  colonies  with  a 
somewhat  opalescent  appearance.    They  are  very  finely  granu- 


172  SUPPURATION- PUS  COCCI. 

lar.  In  a  gelatin  stab  many  small  colonies  form  along  the 
needle-track,  and  on  the  surface  a  little  projection  or  button 
is  formed,  the  typical  nail-growth.  On  potato  the  growth  is 
very  luxuriant. 

Pathogenesis:  The  tetracoccus  is  pathogenic  for  animals  but 
not  for  man.  It  is  very  fatal  for  white  mice  in  the  labora- 
tory. Lartigau  believ^es  that  Micrococcus  tetragenus  may  be 
the  cause  of  a  pseudomembranous  angina.  He  has  observed 
three  cases  of  this  kind.  The  tetracoccus  is  frequently  seen 
in  specimens  of  tubercular  sputum.  Its  shape  is  very  char- 
acteristic and  cannot  fail  to  attract  attention. 


CHAPTEE   II. 

SUPPURATION  {(Continued). 

Micrococcus  Gonorrhoeae. 

NeisseRj  in  1879,  observed  an  organism  in  the  purulent 
discharge  of  gonorrhoea  and  purulent  ophthalmia  which  he 
named  the  gonococcus.  It  was  not  cultivated  and  studied  in 
pure  culture,  however,  until  1885.  It  is  seen  in  pairs,  a 
diplococcus ;  although  occasionally  it  forms  tetrads,  probably 
just  after  division  of  the  diplococcus.  The  approximated 
surfaces  of  the  cocci  are  slightly  concave  or  flat,  and  almost 
touch,  giving  the  organism  a  rather  characteristic  appearance, 
from  which  it  has  been  dubbed  the  "  biscuit  coccus,^'  or,  as 
the  Germans  say,  "  semmel-kokken." 

Biology  and  morphology  :  The  gonococcus  measures  from 
0.8  IX  to  1.6  fi  in  length,  and  from  0.6  /i  to  0.8  [i  in  breadth. 
It  is  not  flagellated ;  nor  is  it  motile ;  and  it  reproduces 
itself  by  binary  division.  It  has  never  been  seen  to  form 
spores.  It  is  stained  readily  by  all  the  anilin  dyes  (Fig.  73), 
but  isjH-onTptly  decolorized Jbyjiram/s_stain^  This  is  a  very 
important  point  in  the  differentiation  of  the  gonococcus  from 
the  pneumococcus  and  meningococcus.  Methylene-blue  is  the 
best  stain  for  specimens  made  directly  from  the  purulent  dis- 
charge. Eosin  may  be  used  as  a  contrast-stain.  It  is  a  fac- 
ultative anaerobe. 

It  is  very  difficult  to  grow  the  gonococcus  artificially.  The 
temperature  must  be  that  of  the  body,  37°  C,  and  even  then 
the  growth  develops  very  slowly  and  sparsely.  Except  for 
experimental  purposes,  it  is  not  necessary  to  make  cultures  of 
the  gonococcus,  as  it  is  easily  recognized  (Fig.  74)  in  stained 
specimens  mounted  directly  from  the  discharges  of  a  gonor- 
rhoeal  inflammation. 

173 


174  SUPPURATION. 


Fig.  73. 


/       4 


1*      ■ 


Smear  from  pure  culture  of  gonococcus  on  agar.    (Heiman.) 

Plates  are  made   in   the  usual  way,  but  instead  of  agar  or 
gelatin,  a  mixture  consisting  of  equal  parts  of  liquid  human 


Fig.  74. 


^m^ 


f 


Gonococcus  in  pus-cells.    X  1100.    (Park.) 

blood-serum  and   2  per  cent,  peptone-agar  is  used.     Within 
twenty-four  hours  a  few  very  small  dry  colonies  are  seen  on 


MICROCOCCUS  G ONORRHCEM 


175 


the  surface  of  the  medium.  These  colonies  are  very  finely 
granular  and  have  a  punctate  centre  (Fig.  75).  The  deeper 
colonies  are  very  nodular  and  are  of  a  grayish-white  color. 
In  a  few  days  the  colony  looks  like  a  blackberry. 

On  blood-serum  agar  (1  part  of  liquid  blood-serum  and  3 
parts  of  agar  solidified  in  the  slanting  position)  a  luxuriant 
growth  is  formed  along  the  line  of  inoculation,  consisting  of 
individual  grayish  colonies,  which  finally  coalesce  to  form  a 
moist,  sticky,  glistening  deposit.  1  part  of  human  blood- 
serum  and  2  parts  of  peptone-bouillon  are  also  a  good  culture- 

FiG.  75. 


Colonies  of  gonococci  on  pleuritic  fluid  agar.    (Heiman.) 


medium.    A  pellicle  forms  on  its  surface,  the  medium  remain- 
ing transparent. 

Other  media  which  have  been  used  in  the  cultivation  of 
this  germ  are  :  a  mixture  of  urine  and  blood-serum  ;  2  parts 
of  peptone-agar  and  1  part  of  acid  human  urine ;  1  part  of 
ascitic  fluid;  and  1  part  of  nutrient  glycerin-agar.  Wertheim 
uses  a  mixture  of  placental  blood-serum  and  2  parts  of  pep- 
tone-agar for  making  pure  cultures  of  the  gonococcus. 
Hydrocele  fluid  and  the  serous  efl^usion  of  pleurisy  have  been 
used  either  alone  or  in  combination  with  other  media.  Acid 
urine  or  urine  mixed  with  gelatin  is  also  suitable. 


176  SUPPURATION. 

The  gonococcns  cannot  be  grown  on  potato,  plain  gelatin, 
or  agar-agar.  It  must  be  remembered  that  the  growth  is 
never  very  heavy.  The  results  obtained  with  cultures  are  so 
variable  that  it  is  impossible  to  describe  any  characteristic 
appearance  other  than  that  seen  in  the  plates. 

Pathogenesis:  The  gonococcus  is  always  found  in  the  puru- 
lent discharge  from  gonorrhoeal  inflammations,  and  the  posi- 
tion of  the  germ  within  the  pus-cells  is  absolutely  characteris- 
tic and  a  point  in  diagnosis.  It  must  be  borne  in  mind  that 
gonorrhceal  inflammations  are  not  limited  to  the  urethral  canal, 
but  may  occur  in  any  part  of  the  body.  These  inflammations 
are  always  very  serious,  and  should  not  be  discussed  lightly 
nor  in  a  facetious  spirit.  In  old  cases  of  gonorrhoea  it  is  occa- 
sionally impossible  to  find  the  gonococcus  in  the  discharges 
because  of  its  position  within  the  tissue-cells  covering  the 
mucous  membrane  of  the  urethra  or  other  parts  of  the  body. 
This  enclosure  serves  as  a  protecting  barrier  to  the  germ.  If 
the  gonococcus  cannot  be  found,  it  is  advisable  to  irritate  the 
mucous  membrane  with  instruments,  such  as  the  passage  of 
sounds  in  the  urethra,  so  as  to  induce  free  secretion.  If  the 
gonococcus  is  contained  in  the  cells,  such  irritation  will 
usually  dislodge  some  cells  and  the  germ  will  appear  in  the 
discharge. 

The  gonococcus  is  constantly  present  in  all  stages  of  the 
disease,  and  in  large  numbers  during  the  acute  stage.  It  is 
also  present  in  the  sequelae  of  gonorrhoea.  It  is  never  present 
under  normal  conditions,  although  a  number  of  organisms 
which  resemble  the  gonococcus,  but  which  differ  as  to  patho- 
genicity and  also  in  culture,  are  frequently  found  in  the 
vaginal  and  urethral  discharges. 

The  gonococcus  will  not  develop  on  healthy  mucous 
membranes.  The  conditions  suitable  for  its  development 
must  exist.  Congestion  of  these  membranes  furnishes  the 
necessary  conditions.  Once  it  has  found  lodgement  on  or  in 
a  mucous  membrane  it  is  exceedingly  difficult  to  dislodge  it. 
The  cessation  of  the  purulent  discharge  is  by  no  means  an 
indication  of  the  disappearance  of  the  gonococcus.  The 
gonococcus  is  very  resistant  to  heat  and  chemicals.  It  also 
has   a   tendency  to  remain    latent  in   the  tissues  for  a  long 


MICROCOCCUS  CITREUS  CONGLOMERATUS.  177 

time,  even  years,  and  yet  retain  its  usual  pathogenic  power. 
The  purulent  inflammation  may  have  subsided  entirely,  and 
the  patient  is  apparently  free  from  the  disease,  and  yet  it  is 
possible  to  find  the  gonococcus  in  the  mucous  secretions  if 
the  membrane  is  irritated  as  previously  described.  A  reap- 
pearance of  the  gonorrhcBal  discharge  is  not  necessarily  the 
result  of  reinfection,  but  may  be  evidence  of  renewed  activity 
of  the  dormant  germ. 

The  gonococcus  is  a  very  virulent  germ.  Its  toxin  is 
extremely  toxic,  and  treatment  must  be  thorough  and  con- 
tinued for  a  long  time  to  insure  a  complete  cure.  The 
gonococcus  is  never  the  cause  of  abscess- formation.  It  is 
said  that  the  germ  cannot  penetrate  membranes  covered  by 
columnar  epithelium.  This  belief  is  apparently  confirmed 
by  the  fact  that  urethral  gonorrhoea  is  never  met  with  in  the 
female,  the  female  urethra  being  lined  with  columnar  epithe- 
lium. In  gonorrhoea  the  entire  vulva,  including  the  urethral 
papillae,  is  constantly  bathed  in  pus,  and  yet  the  disease  rarely 
extends  to  the  urethral  canal. 

The  characteristic  biscuit  shape,  the  position  of  the  germ 
within  the  cells,  and  its  failure  to  stain  with  Gram,  make  a 
positive  diagnosis  of  it  being  the  gonococcus  justifiable. 

Micrococcus  Citreus  Conglomeratus. 

This  germ  is  found  in  the  urethra  and  vagina  in  health  as 
well  as  in  disease.  It  resembles  the  gonococcus  in  appear- 
ance, but  differs  in  culture.  It  can  be  cultivated  easily  on 
all  the  ordinary  culture-media,  forming  a  solid  yellow  growth 
on  solid  media.  Gelatin  is  rapidly  liquefied.  It  is  stained 
by  Gram's  method. 

Other  organisms  which  resemble  the  gonococcus,  and  which 
are  also  found  in  the  vaginal  and  urethral  secretions,  are 
MiGrocoGGUs  subflavus,  DiploGoccus  albicans  amplus,  and  Dip- 
locoGGUs  albiGans  tardissimus.  They  are  all  stained  by  Gram's 
method,  are  not  found  within  the  cells,  and  rapidly  liquefy 
gelatin.  They  form  luxuriant  growths  on  all  ordinary  media. 
We  mention  these  various  organisms  for  the  purpose  of  em- 
phasizing the  importance  of  making  an  absolute  diagnosis  as 

12— Bact. 


178  SUPPURATION. 

to  the  exciting  cause  in  all  cases  of  purulent  inflammations 
of  the  urethra  and  vagina.  The  condition  may  be  due  to 
one  of  these  germs  and  not  to  the  gonococcus. 

Diplococcus  Intracellularis  Meningitidis. 

Meningitis  may  be  due  to  a  variety  of  organisms.  There 
are  streptococcus  meningitis,  tubercular  meningitis,  pneu- 
mococcus  meningitis,  and  a  form  which  is  caused  by  a  specific 
germ,  the  Diplococcus  intracellularis  meningitidis.  The  three 
varieties  first  mentioned  are  usually  secondary  to  disease  in 
some  other  part  of  the  body ;  whereas  the  last  is  a  primary 

Fig.  76. 


X 


% 


Diplococcus  intraceUularis  meningitidis.    X  1100.    (Park.) 

seropurulent  inflammation  of  the  meninges  of  the  brain  and 
cord,  which  was  first  described  by  Weichselbaum  in  1887. 
This  meningococcus  is  the  specific  cause  of  epidemic  cerebro- 
spinal meningitis,  and  is  of  special  interest  because  of  its 
resemblance  to  the  pneumococcus  and  the  gonococcus. 

Biology  and  morphology:  In  form  it  is  a  diplococcus  of  the 
same  shape  as  the  gonococcus,  and  it  is  also  enclosed  within 
the  leucocytes  and  tissue-cells  (Fig.  76).  Occasionally  it  is 
seen   to  occur  singly  or,  like  the  gonococcus,  in  tetrads  or 


DIPLOCOCCUS  INTBACELLULARIS  MENINGITIDIS.     179 

fours.  It  is  readily  stained  with  the  anilin  dyes,  especially 
Loeffler's  alkaline  methylene-blue,  and  is  decolorized  by 
Gram's  stain.  It  does  not  form  spores,  has  no  flagella,  and 
is  not  motile.  It  differs  from  the  gonococcus  in  that  it  is 
very  easily  cultivated. 

The  meningococcus  grows  well  on  agar-agar  and  on  glycerin- 
agar,  but  not  on  potato,  nor  in  gelatin  or  bouillon.  It  grows 
very  luxuriantly  on  Loeffler's  blood-serum  mixture,  but  not 
at  all  in  a  mixture  of  bouillon  and  blood-serum.  It  abso- 
lutely requires  a  temperature  equal  to  that  of  the  body.  It 
is  a  facultative  anaerobe. 

In  tube  cultures  it  forms  minute  round  colonies  having  a 
very  sharply  defined  regular  border.  The  colonies  are  shin- 
ing and  almost  translucent,  and  of  a  grayish-white  color. 
They  very  closely  resemble  streptococcus  colonies  on  an  agar 
slant.     The  medium  is  not  liquefied. 

On  agar-agar  tubes  or  plates  deep  and  superficial  colonies 
are  formed.  The  deep  colonies  are  hardly  visible.  The 
superficial  colonies  are  round,  flat,  and  very  finely  granular, 
with  dentate  edges.  They  are  yellowish-brown  in  color,  and 
darker  in  the  centre  than  at  the  periphery. 

The  meningococcus  possesses  very  little  resistance  to  either 
heat  or  chemicals,  and  dies  very  rapidly  in  culture  unless 
frequently  transplanted. 

Pathogenesis:  The  meningococcus  is  pathogenic  for  man 
and  animals.  Weichselbaum  concluded  that  infection  occurred 
through  the  ear  and  upper  air-passages,  especially  the  nose. 
He  succeeded  in  obtaining  the  diplococcus  in  pure  culture 
from  the  nasal  secretions  of  one  case  out  of  his  series  of  six. 
It  has  also  been  found  in  the  nares  of  healthy  individuals  and 
in  a  few  cases  of  conjunctivitis.  It  has  been  found  present 
in  about  50  per  cent,  of  all  cases  of  cerebrospinal  meningitis. 

The  bacteriologic  diagnosis  is  made  by  examining  the  fluid 
obtained  from  the  spinal  canal  by  means  of  lumbar  puncture. 
Park  says  that  such  a  diagnosis  is  of  clinical  value,  because 
about  40  per  cent,  of  all  cases  of  meningitis  due  to  this  coccus 
recover,  while  nearly  all  the  cases  due  to  the  pneumococcus 
and  streptococcus  end  fatally. 

Cultures  may  also  be  made  from  the  pus  obtained  from  the 


180  SUPPURATION. 

spinal  canal  at  the  autopsy.  A  large  amount  of  the  spinal 
fluid  should  be  used,  as  ordinarily  it  contains  very  few  living 
germs. 

Lumbar  puncture :  Have  the  patient  lie  on  the  right  side, 
with  the  knees  drawn  up  and  the  left  shoulder  depressed, 
the  same  position  which  he  would  assume  when  squatting 
on  his  haunches.  The  site  of  puncture,  the  instruments, 
and  the  operator's  hands  should  be  carefully  cleansed  and 
disinfected.  The  needle  should  be  of  sufficient  length — 
at  least  four  centimeters,  and  have  a  long  bevel.  Locate 
the  interspinous  space  between  the  third  and  fourth  lum- 
bar vertebrae  and  insert  the  needle  slowly,  about  one  cen- 
timeter to  the  right  of  the  median  line  and  directed  slightly 
upward  and  inward  toward  the  median  line.  Pressure  is 
continued  until  the  needle  enters  the  subarachnoidean  space, 
which  is  made  evident  by  the  outflow  of  a  few  drops  of  cere- 
brospinal fluid.  About  5-15  c.c.  of  this  fluid  are  collected 
in  sterile  tubes.  Care  must  be  taken  not  to  introduce  the 
needle  too  far,  and  not  to  draw  blood,  which  interferes  with 
the  examination. 

The  needle  must  be  introduced  without  any  wiggling,  and 
when  it  meets  with  an  obstruction  it  should  be  immediately 
withdrawn  and  inserted  again.  The  puncture  is  sealed  with 
collodion.  Patients  experience  no  ill  eff'ects  from  this  pro- 
cedure. 

Diplococcus  Lanceolatus. 

This  organism  is  also  known  as  Micrococcus  lanceolatus. 
Diplococcus  pneunio7ii(E,  and  the  pneumococcus  of  Fraenkel, 
It  is  found  in  about  75  per  cent,  of  all  cases  of  lobar  or 
croupous  pneumonia,  and  is  accepted  as  the  specific  cause  of 
that  affection,  although  it  has  been  manifestly  impossible  to 
meet  all  the  requirements  of  Koch's  law  as  to  specificity. 
Its  morphology  is  extremely  variable,  and  hence  its  many 
names  (Fig.  78). 

Biology  and  morphology  :  The  pneumococcus  (as  it  is  usually 
designated)  is  an  oval  coccus  which  usually  occurs  in  pairs. 
Sometimes  it  forms  short  chains  of  four  or  five,  when  it  may 
be  mistaken  for  the  streptococcus.     Each  coccus  has  a  leaf- 


DIPLOCOCCUS  LANCEOLATUS.  181 

or  lance-shaped  extremity,  but  this  shape  is  seen  only  in  the 
disease  product,  and  not  in  culture.  Here  the  organism  has 
more  or  less  of  an  oval  or  spherical  shape.  Each  diplococcus 
in  its  native  state  is  also  surrounded  by  a  capsule  (Fig.  77). 
When  the  germ  is  cultivated,  the  capsule  is  not  visible.  It  is 
not  motile,  has  no  flagella,  and  does  not  sporulate.  It  stains 
with  the  anilin  dyes  and  by  Gram's  method,  differing  in  that 
respect  from  both  the  gonococcus  and  the  meningococcus.  It 
is  a  facultative  anaerobe. 

Although  the  pneumococcus  will  grow  at  a  temperature  as 
low  as  71°  F.,  its  temperature  optimum  is  more  nearly  the 

Fig.  77. 


Diplococcus  of  pneumonia,  with  surrounding  capsule.    (Park.) 

temperature  of  the  body.  A  ten  minute  exposure  to  a  tem- 
perature of  52°  C.  kills  the  germ.  The  conditions  in  culture 
must  be  absolutely  favorable  to  the  development  of  the  germ, 
as  it  possesses  but  little  vitality  outside  of  the  body. 

The  pneumococcus  was  observed  first  by  Sternberg  in  the 
saliva  of  healthy  persons.  For  culture  purposes  it  is  obtained 
best  directly  from  pneumonic  sputum.  A  rabbit  is  inoculated 
with  the  sputum,  and  after  a  few  hours  the  germ  is  obtained 
from  the  blood  of  the  animal.  Kitasato  advises  washing  the 
sputum  of  the  pneumonic  patient  in  sterile  water  until  it  has 
been  freed  from  all  contaminating  oro^anisms,  then  separating 
the  mass  and  transplanting  its  central  portion  to  the  culture- 
medium. 


182  SUPPURATION. 

It  grows  fairly  well  on  all  the  ordinary  culture- media 
except  potato ;  but  its  growth  is  somewhat  retarded  by  the 
formic  acid  which  the  organism  produces  in  the  course  of  its 
development.  It  is  desirable  for  this  reason  to  have  a  slightly 
alkaline  medium.  Like  the  meningococcus,  it  must  be  trans- 
planted frequently  in  order  to  preserve  its  vitality.  It  is 
extremely  sensitive  to  antiseptics  and  disinfectants. 

A  mixture  consisting  of  one-third  ascitic  or  pleuritic  fluid 
and  two-thirds  bouillon  is  the  best  culture-medium.     When 

Fig.  78. 


Pneumococcus  from  bouillon  culture,  resembling  streptococcus.    (Park.) 

inoculated  into  this  medium  and  then  placed  on  ice,  the  pneu- 
mococcus will  retain  its  vitality  as  well  as  its  virulence  for 
months.  31ilk  is  coagulated  rapidly.  The  high  temperature 
required  for  the  growth  of  this  organism  makes  it  necessary 
to  use  a  greater  percentage  of  gelatin  culture-medium  ;  15  or 
20  per  cent,  will  not  melt  at  a  temperature  of  24°  C.  When 
plated  in  this  medium  very  minute  round  and  finely  granular 
white  specks  appear.  On  agar-agai'  plates  the  colonies  are  so 
transparent  as  to  be  scarcely  perceptible.  They  are  granu- 
lated and  have  a  dark  central  portion. 

In  the  gelatin  tube  culture  little  whitish  colonies  form  along 


DIPLOCOCCUS  LANCEOLATUS.  183 

the  entire  stab.  They  remain  distinctly  separate.  Its  lim- 
ited growth  is  apparent  even  in  the  most  suitable  medium. 
On  agar-agar  and  blood-serum  the  growth  is  often  overlooked, 
the  colonies  are  so  very  small  and  transparent.  Bouillon  is 
slightly  clouded.  Agar-agar  may  be  covered  with  a  thin 
film  of  blood-serum  and  used  for  a  culture-medium.  When" 
desirable  to  increase  the  virulence  of  the  germ,  it  must  be 
passed  through  animals. 

The  development  of  the  diplococcus  is  checked  by  a  1  :  400 
solution  of  boric  acid ;  1  :  20,000  mercuric  chloride  solution 
or  a  1  per  cent.  solutiorTo^F carbolic  aciti  destroys  its  vitality 
in  two  hours.  In  the  dry  state  it  retains  its  virulence  for  a 
long  time.  This  is  of  importance  when  considering  the 
methods  of  infection. 

Pathogenesis  :  The  pneumococcus  is  always  found  in  the 
rusty  sputum  of  lobar  pneumonia,  and  is  usually  associated 
with  other  germs,  especially  the  streptococcus  and  staphylo- 
coccus. It  has  also  been  found  in  meningitis,  sore  throat, 
endocarditis,  otitis  media,  acute  abscess,  and  in  the  sequelae 
of  croupous  pneumonia.  The  bloodvessels  and  the  lymph- 
atics, especially  the  latter,  carry  the  germ  to  other  parts  of 
the  body  from  the  original  site  of  infection. 

Injection  usually  occurs  through  the  respiratory  tract, 
although  in  secondary  pneumonia  the  pneumococcus  may  find 
its  way  to  the  lung  through  the  bloodvessels.  But  this 
method  of  infection  is  extremely  infrequent.  The  air  con- 
veys the  germ  from  ])lace  to  place,  and  thus  gives  rise  to 
epidemics  of  pneumonia.  In  order  to  prevent  this  dissemina- 
tion it  is  absolutely  necessary  to  prevent  desiccation  of  the 
germ,  and  this  can  only  be  done  by  receiving  the  sputum  in 
a  proper  receptacle  containing  an  antiseptic  solution.  This 
solution  not  only  prevents  drying,  but  it  also  kills  the  germ. 
A  2  per  cent,  carbolic  acid  solution  answers  the  purpose 
admirably.  Neglect  of  these  precautions  is  undoubtedly 
responsible  for  the  so-called  house  epidemics  of  pneumonia, 
several  instances  of  which  have  been  recorded. 

In  view  of  the  fact  that  the  pneumococcus  may  be  found 
in  the  mouths  of  healthy  individuals,  it  is  evident  that  condi- 
tions predisposing  to  infection  must  exist  before  the  disease 


184  SUPPURATION. 

will  develop.  The  presence  of  the  germ  under  normal  con- 
ditions would  also  account  for  those  isolated  cases  of  pneu- 
monia occurring  in  individuals  who  have  not  been  exposed 
to  infection,  and  who  have  not  come  in  contact  with  a  case 
of  pneumonia.  The  possibility  of  contracting  the  disease 
has  been  present  all  the  time  and  under  favorable  conditions 
the  germ  has  become  active.  A  few  instances  of  transmission 
from  the  mother  to  the  foetus  through  the  placenta  have  been 
recorded. 

Immunity:  It  is  believed  by  most  investigators  that  immu- 
nity after  an  attack  of  pneumonia  is  present  in  a  very  slight 
degree  and  is  of  only  short  duration,  or  that  it  never  exists. 
The  brothers  Klemperer  isolated  a  substance  from  the  serum 
of  immunized  rabbits  which  protected  animals  inoculated  with 
the  pneumococcus.  They  called  this  substance  pneumoprotein. 
Washburne  also  prepared  an  antipneumococcus  serum  by  in- 
oculating a  horse  with  virulent  pneumococci.  It  appeared  to 
be  superior  to  the  serum  of  the  Klemperers  inasmuch  as  it 
exerted  a  protective  action  in  the  human  being  as  well  as  in 
animals.  This  question  of  immunization  against  the  pneumo- 
coccus is  still  largely  a  matter  of  conjecture ;  but  further 
investigation  will  undoubtedly  place  the  antipneumococcus 
serum  on  a  firmer  foundation,  at  least  so  far  as  the  pre- 
vention of  the  disease  is  concerned. 

The  use  of  the  serum  for  therapeutic  purposes  has  been 
attended  with  good  results  in  the  hands  of  a  few  clinicians ; 
although  in  the  great  majority  of  instances  the  injection  of 
even  a  large  amount  of  serum  does  not  appear  to  have 
altered  the  course  of  the  disease  in  any  way.  The  dyspnoea 
was  lessened,  but  no  other  change  was  noted.  It  is  perfectly 
harmless  even  in  large  doses,  so  that  its  use  is  not  attended 
with  danger.  Another  author,  in  an  experience  with  106 
cases  of  lobar  pneumonia,  found  that  it  lowered  the  tempera- 
ture, relieved  the  pain,  ameliorated  all  the  symptoms,  and 
hastened  the  crisis.  The  number  of  cases  in  which  the 
serum  has  been  used  for  therapeutic  purposes  is  so  small, 
however,  that  it  is  impossible  to  express  any  opinion  as  to  its 
value  either  as  a  curative  or  preventive  agent. 


BACILLUS  OF  FRIEDLAENDER, 

Bacillus  of  Friedlaender. 


185 


When  Friedlaender  discovered  this  organism  in  the  sputum 
of  pneumonia  patients  he  believed  it  to  be  the  specific  cause 
of  the  disease.     Further  investigation  disclosed  the  fact  that 


Fig.  79. 


Fig. 


Fig.  81. 


Fig.  82. 


Bacillus  of  Friedlaender  (Colonies). 


186  SUPPURATION. 

it  is  an  associated  organism  in  only  a  very  small  percentage 
of  the  cases  of  lobar  pneumonia. 

Morphology  and  biology :  The  pneumobacillus  is  a  very 
short  bacillus  with  rounded  ends,  occurring  in  pairs  or  chains. 
The  germ  at  times  is  so  short  as  to  resemble  a  coccus,  and 
when  seen  in  pairs  it  may  be  mistaken  for  the  pneumococcus. 
In  the  sputum  it  is  surrounded  by  a  capsule.  It  stains  with 
all jthe  anilin  dyes,  but  jiot  by  Gram's  method.  It  does  not 
sporulate,  is  non-motile,  and  has  no  flagella.  It  is  a  faculta- 
tive anaerobe,  growing  equally  well  at  the  temperature  of  the 
body  or  the  room  temperature. 

On  gelatin  plates  it  forms  minute  porcelain-like  colonies, 
which  have  a  very  regular  outline  and  are  finely  granular. 
On  agar-agar  plates  the  colonies  are  much  larger,  moist,  and 
of  a  grayish  color.  In  the  gelatin  stab  a  typical  nail  growth 
is  seen  (Figs.  79-82).  The  medium  is  not  liquefied.  A  thick, 
heavy,  moist  growth  is  formed  on  agar  slants.  On  potgia  a 
very  luxuriant  yellowish  growth  develops  which  soon  covers 
the  entire  surface  of  the  potato.  It  does  not  coagulate  milk. 
It  causes  fermentation  in  media  containing  grape-sugar  or 
milk-sugar.  It  produces  aromatics,  especially  indol.  Gas 
bubbles  are  occasionally  formed  in  the  gelatin  cultures. 

Pathogenesis  :  The  bacillus  has  been  found  in  the  mouth 
and  throat  of  healthy  individuals,  in  the  ear,  and  in  the 
sputum  of  lobar  pneumonia  associated  with  the  pneumococ- 
cus ;  also  in  gangrene  of  the  lung,  catarrhal  pneumonia, 
malignant  endocarditis,  and  the  conditions  already  mentioned. 


CHAPTEK   III. 

BACILLUS  TUBERCULOSIS. 

The  Bacillus  tuberculosis  is  the  specific  cause  of  all  tuber- 
cular processes.  It  is  one  of  the  most  commonly  occurring 
germs,  and  therefore  also  one  of  the  most  dangerous.  As 
early  as  1868  Villemin  showed  that  tubercuh)sis  was  an 
infectious  disease,  and  that  it  might  be  produced  experimen- 
tally by  injecting  tuberculous  matter  into  healthy  animals. 
Cohnheim  later  confirmed  these  findings,  and  in  1882  Robert 
Koch  discovered  the  tubercle  bacillus  and  succeeded  in  culti- 
vating it. 

The  tubercle  bacillus  is  found  in  all  tubercular  lesions  and 
in  the  sputum  of  patients  suffering  from  pulmonary  or  laryn- 
geal tuberculosis  ;  in  the  milk  of  tubercular  cows  ;  in  rooms 
inhabited  by  tubercular  patients  (unless  proper  precautions 
are  taken)  who  are  not  careful  as  to  the  disposition  of  their 
sputum ;  in  food,  especially  the  meat  of  tubercular  cattle ; 
and  in  the  milk  of  a  tubercular  mother.  It  may  also  be 
found  in  the  excretions  of  animals  and  persons  suffering  from 
intestinal  tuberculosis;  further,  in  all  places  and  convey- 
ances where  tubercular  persons  expectorate  promiscuously, 
thus  favoring  desiccation  of  the  sputum  and  dissemination 
of  the  bacillus. 

Biology  and  morphology:  The  tubercle  bacillus  is  a  very 
slender,  rod-shaped  organism,  1.5  fi  to  4  fi  in  length,  and 
0.2  fi  to  0.4  n  wide.  It  has  rounded  ends,  and  frequently 
is  slightly  curved.  It  is  non-motile  and  has  no  flagella.  It 
may  oe  seen  in  a  variety  of  arrangements.  Usually  it  occurs 
singly ;  but  it  may  be  paired  or  form  chains  of  three  or 
four,  especially  in  culture.  At  times  the  bacillus  may  be 
clubbed  at  one  end,  or  it  may  exhibit  central  bulging  sugges- 
tive of  sporulation.     This  appearance  of  sporulation  is  more 

187 


188  BACILLUS  TUBERCULOSIS. 

marked  in  the  case  of  those  organisms  which  stain  irregularly 
and  present  unstained  areas,  giving  the  bacterium  a  beaded 
appearance.  This  variety  is  usually  seen  only  in  old  cultures 
or  in  the  sputum  of  chronic  cases  of  pulmonary  tuberculosis. 
It  probably  represents  an  involution-form  or  a  degeneration 
of  the  bacterium.  The  special  spore-staining  methods  are  not 
applicable.  In  these  cases  the  peculiar  branching  or  fila- 
mentous forms  of  the  tubercle  bacillus  are  also  seen.  These 
forms  have  suggested  a  relationship  between  the  tubercle 
bacillus  and  the  actinomyces.  For  this  reason  the  tubercle 
bacillus  has  been  placed  by  some  a_mong  the  streptothrixes, 
and  the  name  mycobacterium  has  been  suggested  as  being 
more  correct  than  the  appellation  bacillus. 

A  most  remarkable  characteristic  of  the  tubercle  bacillus, 
and  one  which  serves  to  differentiate  it  from  all  similar  org.an- 
isms,  is  its  behavior  to  certain  staining  solutions.  It  is  stained 
with  great  difficulty,  but  once  it  has  taken  up  the  stain  it  is 
almost  impossible  to  decolorize  it.  Koch  first  used  an  anilin 
dye  to  which  he  added  potassium  hydrate.  Ehrlich  modified 
this  method  by  staining  with  an  anilin  dye  to  which  a  satu- 
rated aqueous  solution  of  anilin  oil  was  added,  and  then 
decolorizing  with  a  strong  mineral  acid,  which  removed  the 
stain  from  everything  except  the  tubercle  bacillus.  This  was 
followed  by  a  contrast-stain.  This  method  has  been  modified 
in  various  ways  by  others,  but  the  principle  of  overstaining 
and  decolorizing  with  a  mineral  acid  is  the  same  in  all  the 
methods.  The  Ziehl-Neelson  method  is  probably  the  best. 
Gram's  stain  is  also  applicable,  but  is  not  very  satisfactory. 

It  is  very  difficult  to  obtain  the  tubercle  bacillus  in  pure 
culture.  It  is  an  obligate  parasite,  aerol)ic,  and  absolutely 
requires  a  temperature  of  ^7^jC.  for  its  development.  It 
grows  very  slowly  even  under  conditions  favorable  to  its 
development.  Hen's  eggs  are  an  excellent  culture-medium 
for  the  bacillus.  Either  the  yolk  or  the  white,  or  both,  may 
be  used.  Small  round  white  colonies  appear  in  from  ten  to 
fourteen  days.  After  tlic  tubercle  bacillus  has  become  habit- 
uated to  being  cultivated,  it  will  grow  quite  readily  on  veal- 
or  chicken-bouillon. 

It  is  impossible  to  make  a  plate  culture  of  this  germ,  because 


BIOLOGY  AND  MORPHOLOGY.  189 

of  its  slow  growth,  and,  further,  because  the  associated  organ- 
isms outgrow  the  tubercle  germ  and  thus  suppress  its  growth. 
Except  for  experimental  purposes  and  for  the  manufacture 
of  the  various  tuberculin  products,  it  is  not  necessary  to  make 
cultures  of  the  bacillus  ;  but  when  a  pure  culture  is  desired, 
a  special  line  of  procedure  must  be  followed  : 

A  number  of  animals  which  are  very  susceptible  to  tubercular 
infection,  such  as  guinea-pigs,  are  inoculated  with  the  tuber- 
cular material,  at  intervals  of  one  day.  Within  about  four  or 
five  weeks  the  animal  inoculated  first  will  die  from  tubercu- 
losis, which  is  confirmed  at  the  autopsy.  One  of  the  other 
animals  is  then  killed,  and  under  the  strictest  antiseptic  pre- 
cautions its  abdomen  and  peritoneal  cavity  are  opened.  With 
sterile  instruments  the  spleen  is  brought  into  view,  as  this  is 
the  organ  which  usually  Ts  affected  most  by  the  tubercular 
process.  Examine  the  surface  of  the  spleen  for  a  tubercular 
nodule  and  excise  it  with  sterile  scissors.  This  nodule  is  then 
compressed  between  sterile  glass  slides  and  transferred  to 
tubes  containing  blood-serum.  Seal  these  tubes  with  rubber 
caps  and  place  them  in  the  incubator.  It  is  perhaps  needless 
to  caution  the  operator  never  to  allow  his  hands  to  come  in 
contact  with  any  tubercular  material,  as  infection  is  extremely 
liable  to  occur.  Everything  should  be  handled  with  sterile 
instruments,  so  as  to  avoid  contamination  of  the  pure  culture 
of  the  bacillus. 

Pure  cultures  may  also  be  obtained  directly  from  tuber- 
cular sputum.  The  patient's  mouth  is  first  thoroughly  disin- 
fected. He  is  then  instructed  to  expectorate  into  a  sterile 
Petri  dish.  This  sputum  is  subjected  to  repeated  washings 
with  sterile  water  until  all  the  bacteria  whic^h  may  have  been 
lodged  on  the  surface  of  the  sputum  are  removed.  The  mass 
is  next  carefully  separated  with  a  sterile  needle,  its  centre 
removed  and  placed  on  glycerin-agar  or  blood-serum.  After 
two  or  three  weeks  small  grayish-white  scaly  colonies  appear 
on  the  medium.  These  gradually  coalesce  to  form  an  irregu- 
lar scaly  membranous  growth. 

After  the  bacillus  has  become  habituated  to  being  grown 
outside  the  body,  it  is  preferable  to  })erpetuate  the  cultures 
on  glycerin-agar.     The    growth   on   glycerin-agar  resembles 


y 


190  BACILLUS  TUBERCULOSIS. 

that  on  blood-serum,  but  occurs  much  more  rapidly.  In  the 
course  of  time  the  whitish  color  is  replaced  by  a  light  ochre- 
yellow.  The  growth  soon  spreads  to  form  a  heavy  dry  film 
which  covers  the  entire  surface  of  the  medium  and  at  times 
extends  up  the  sides  of  the  tube  for  a  short  distance. 

When  transplanted  into  veal-boicillon  or  glycerin-veal-bouillo7iy 
a  membrane  resembling  that  seen  on  solid  media  is  formed.  A 
characteristic  of  the  growth  in  fluid  media  is  that  develop- 
ment is  limited  to  the  surface,  leaving  the  medium  perfectly 
clear.  The  tubercle  bacillus  requires  oxygen  for  its  growth, 
and  therefore  will  not  grow  beneath  the  surface  of  the  culture. 

Cultures  may  also  be  made  on  potatoes  which  are  partly 
submerged  in  a  5  per  cent,  glycerin  and  0.5  per  cent,  sodium 
chloride  solution.  A  heavy  film  is  formed  on  the  potato  and 
on  the  surface  of  the  glycerin  and  salt  solution.  The  fluid 
remains  unclouded.  Still  another  medium  on  which  the 
tubercle  bacillus  can  be  grown  is  a  mixture  of  commercial 
ammonium  carbonate,  5  per  cent. ;  primary  potassium  sul- 
phate, 0.15  per  cent.;  magnesium  sulphate,  2.5  per  cent.; 
glycerin,  1.5  per  cent. 

Vitality  of  the  germ :  A  ten-minute  exposure  to  a  tempera- 
ture of  70°  C.  kills  the  germ ;  95°  C.  is  fatal  in  one  minute. 
It  is  not  aifected  by  cold.  Direct  sunlight  is  fatal  in  a  very 
short  time,  depending  on  the  amount  of  material  exposed. 
This  effect  on  the  germ  of  the  sun^s  rays  is  now  being  made 
use  of  in  the  treatment  of  tuberculosis.  Patients  are  exposed 
to  the  direct  rays  of  the  sun  in  so-called  "  sun  parlors'^  for  as 
long  a  time  during  the  day  as  possible ;  or  exposure  is  made 
to  the  concentrated  rays  for  a  short  time.  The  supposition 
is  that  the  germ  will  be  either  destroyed  or  inhibited  in  its 
growth,  and  that  the  system  will  thus  have  an  opportunity  to 
overcome  the  infection.  The  germ  resists  diffused  daylight 
for  a  week  or  longer.  Desiccation  at  ordinary  temperatures  is 
also  resisted  for  a  long  time.  Dry  heat  kills  more  slowly 
than  moist  heat.  Bacteria  placed  in  water  at  a  temperature 
of  95°  C.  are  killed  in  one  minute,  whereas  dry  heat  at  a 
temperature  of  100°  C.  is  often  ineffective  after  an  exposure 
of  several  hours.  The  bacilli  contained  in  tubercular  sputum 
are  killed  by  a  3  per  cent,  solution  of  carbolic  acid  in  about 


PLATE   III. 


FIG.  1. 


/V 


y  ^// 


Tubercle  bacilli,  in  red. 
Stpepto-baeilli,  in  blue.    (Park.) 

X  iioo  diameters. 


FIG.  2 
/ 


Tubercle  bacilli,  in  red. 
Tissue,  in  blue.    (Park  ) 

X  IIOO  diameters. 


FIG    3 


Very  large  tubercle  bacilli.    Cells  in  specimen  are 
in  blue,  while  bacilli  are  red.    (Park.) 

X  IIOO  diameters. 


PATHOLOGIC  ANAT03fY  OF  TUBERCLE  BACILLUS.   191 

six  hours ;  by  a  5  per  cent,  solution  in  about  one  hour.  The 
germ  in  the  sputum  is  active  for  a  long  time,  and  infection 
may  occur  after  two  or  three  months. 

Pathogenesis  :  The  tubercle  bacillus  is  the  exciting  cause  of 
tuberculosis  in  man  as  well  as  in  animals.  It  is  a  matter 
under  discussion  whether  the  organisms  which  cause  tuber- 
culosis in  fish,  birds,  and  cattle,  are  distinct  species  from 
Bacillus  tuberculosis  of  man ;  or  whether  they  are  aberrant 
types  of  the  same ;  or  a  modification  of  this  germ  due  to 
changed  surroundings — a  question  of  adapting  itself  to  its 
environment.  It  is  a  rather  remarkable  and  at  the  same 
time  significant  fact  that  animals  which  in  their  native  state 
are  immune  to  tuberculosis,  succumb  very  rapidly  to  the 
infection  as  soon  as  they  are  kept  in  captivity.  The  monkey 
is  an  excellent  illustration  of  this.  Nearly  all  captive 
monkeys  die  from  tuberculosis,  whereas  the  wild  monkey  is 
immune  to  the  disease. 

Guinea-pigs  are  naturally  very  susceptible  to  tuberculosis, 
and  are  used  extensively  for  experimental  and  diagnostic  pur- 
poses. An  injection  of  a  very  small  amount  of  tubercular 
material  into  a  guinea-pig  will  cause  death  in  about  three  or 
four  weeks.  Autopsy  reveals  extensive  tubercular  lesions  in 
which  the  tubercle  bacillus  is  always  found.  Tuberculosis  in 
animals  can  be  produced  by  feeding  them  with  tubercular 
sputum  or  other  material  containing  the  bacillus ;  by  causing 
them  to  inhale  a  very  fine  vapor  spray  in  which  the  bacilli 
are  suspended ;  and  by  inoculation  into  any  part  of  their 
bodies. 

Of  the  domestic  animals,  cattle  and  pigs  are  the  most  sus- 
ceptible. Cold-blooded  animals  are  naturally  immune  unless 
the  bacillus  has  first  been  accustomed  to  grow  at  very  low 
temperatures.  Birds,  with  but  few  exceptions,  are  immune 
to  tuberculosis. 

Pathologic  anatomy  of  the  tubercle  bacillus :  The  tubercle  is 
the  constant  anatomic  product  of  the  tubercle  bacillus.  It  is 
seen  in  all  the  organs  and  tissues.  Lodgement  of  the  bacillus 
in  any  tissue  is  followed  by  the  production  of  many  new  cells, 
w^hich  comprise  both  regular,  fixed,  or  connective-tissue  cells, 
and  modifications  of  the  same-^i.  e.,  the  so-called  epithelioid 


192  BACILLUS  TUBERCULOSIS. 

or  "  epithelial "  cells.  This  mass  of  proliferated  cells  is  sur- 
rounded by  a  zone  of  leucocytes  which  collect  for  the  pur- 
pose of  attempting  to  stay  and  limit  the  infection.  The  entire 
mass  of  cells  constitutes  a  tubercle,  and  represents  a  reaction 
of  the  tissues  to  the  irritation  caused  by  the  tubercle  bacillus 
and  its  toxins.  The  tubercle  bacillus  was  given  its  name 
because  it  is  the  cause  of,  and  is  always  found  in  these  tuber- 
cles.    The  disease  was  named  tubercle-osis  or  tuberculosis. 

The  continued  multiplication  of  the  tissue-cells,  together 
with  the  continued  secretion  of  the  tubercle  toxins  and  the 
growth  of  the  bacillus,  finally  deprives  the  cells  in  the  centre 
of  the  mass  of  their  nutrition,  so  that  they  die  from  starva- 
tion ;  their  death  is  called  necrosis.  Such  death  results  in  a 
cheesy  mass  which  is  surrounded  by  successive  zones  of  pro- 
liferating cells  and  protecting  leucocytes.  Infiltration  with 
lime  salts  may  follow,  or  encapsulation  of  the  tubercular  area, 
when  the  disease  is  said  to  be  cured. 

When  the  tubercle  is  infected  with  streptococci,  there  fol- 
low suppuration,  the  formation  of  cavities  by  expulsion  of  the 
broken-down  material,  and  dissemination  of  the  process  to 
other  parts  of  the  body.  Two  influences  are  constantly  ope- 
rative, the  resistance  of  the  tissues  and  the  destructive  action 
of  the  germ  and  its  products.  Of  these  two  processes,  one  or 
the  other  always  predominates. 

Because  of  their  resemblance  to  a  millet-seed  the  small 
tubercles  are  called  miliary  tubercles.  The  acute  form  of  the 
disease  is  manifested  by  the  formation  of  many  such  small 
growths,  and  is  known  as  miliary  tuberculosis.  These  small 
tubercles  are  grayish  in  color,  and  translucent  and  very  firm. 
As  they  grow  larger  their  centres  degenerate,  and  they  become 
soft  and  yellow.  Diffuse  tubercle  tissue  may  also  be  formed. 
This  is  also  composed  of  many  cells,  but  does  not  tend  to 
remain  localized,  nor  does  it  break  down. 

In  the  acute  tubercular  processes  the  bacilli  are  very  numer- 
ous. In  the  chronic  lesions  they  are  few  in  number,  and 
oftentimes  repeated  examinations  have  to  be  made  before  it  is 
possible  to  discover  the  bacillus.  This  is  especially  true  of 
sputum  examinations. 

Infection :  By  far  the  most  frequent  channel  of  infection  is 


PLATE    IV. 


Tubercular  eruption  in  the  iris  of  a  rabbit,  fifth  day  after 
inoculation.    Zeiss  Via-    (Baumgarten.) 

Beg.  T.  Formation  of  tubercles  beginning  (separation  of  white  corpuscles). 
E.  Endothelium  of  the  anterior  surface  of  the  iris. 
Ep.  Epithelium  of  the  posterior  surface  of  the  iris. 
P.  Iris  parenchyma. 
G/.  Bloodvessels. 


MANNER   OF  INFECTION.  193 

the  respiratory  tract.  The  bacillus  is  inhaled  with  the  im- 
palpable dust  in  which  it  is  contained.  It  was  formerly 
believed  that  all  dust  contained  the  bacillus,  but  this  has 
been  disproved  by  more  recent  investigations,  which  show 
that  it  is  found  only  in  the  dust  of  places  frequented  by  con- 
sumptives. It  is  also  possible,  although  unusual,  to  inhale 
the  germ  directly  from  a  patient  when  he  sneezes  or  coughs. 
The  mucus  which  is  expelled  with  the  effort  may  contain  the 
bacillus.  For  this  reason  the  physician  should  never  stand 
in  front  of  a  patient  when  he  is  conducting  an  examination 
of  the  throat  or  chest.  Patients  should  be  urged  to  cover  the 
face  with  a  cloth  or  handkerchief  when  they  cough  or  sneeze. 
Nuttali  says  that  from  one-half  to  three  billion  virulent 
tubercle  bacilli  are  expectorated  by  a  tubercular  patient  in 
the  course  of  twenty-four  hours.  The  necessity  of  extreme 
precautions  to  prevent  infection,  especially  of  the  medical 
attendant  and  the  patient's  family,  is  very  evident. 

Persons  susceptible  to  tuberculosis  should  be  exceedingly 
careful  not  to  increase  the  liability  of  infection  by  living  with 
a  tubercular  patient  or  consorting  with  him  longer  than 
is  absolutely  necessary.  The  patient  should  do  all  in  his 
power  to  prevent  his  becoming  a  nidus  of  infection  for  others. 
Bacilli  contained  within  a  small  particle  of  mucus  remain 
alive  for  a  long  time,  and  the  danger  of  infection  is  much 
greater  from  this  source  than  from  the  bacilli  contained  in 
dust  which  has  been  exposed  to  light,  and  especially  sunlight, 
for  some  time. 

Personal  susceptibility  is  a  very  essential  factor  in  the  con- 
traction of  the  disease.  It  is  possible  for  a  perfectly  healthy 
individual  to  inhale  the  tubercle  bacillus  without  acquiring 
the  disease.  His  active  phagocytes  will  dispose  of  the  germ. 
At  autopsies  the  bronchial  and  mediastinal  lymph-glands  fre- 
quently present  evidences  of  tubercular  invasion,  although 
the  patients  may  not  have  exhibited  any  symptoms  of  tuber- 
culosis during  their  lifetime.  This  is  an  evidence  of  phago- 
cytosis ;  or  of  infection  with  a  bacillus  which  was  considerably 
attenuated.  It  has  been  said  that  80  per  cent,  of  all  persons 
post-mortemed  show  evidences  of  tubercular  infection,  and 
yet  only  (!)  one-seventh  of  the  population  die  from  tubercu- 

13— Bact. 


194  BACILLUS  TUBERCULOSIS. 

losis.  Of  course,  this  percentage  of  findings  would  be  con- 
siderably less  if  it  were  possible  to  holcl  autopsies  on  all 
the  dead.  The  existence  of  these  lesions,  without  actual 
evidence,  clinically,  of  disease,  is  sufficient  to  warrant  the 
opinion  that  injection  with  attenuated  o^^ganisms  does  occur, 
and  that  even  when  the  bacilli  are  virulent  the  healthy  body 
is  able  successfully  to  ward  off  the  infection.  Individual 
predisposition  is  of  great  importance. 

Persons  not  naturally  susceptible  to  tuberculosis  may  be 
deprived  of  their  resistance  to  the  disease  by  any  of  the 
causes  which  reduce  resistance  to  infection  in  general.  Dia- 
betes and  tuberculosis  are  rarely  found  associated.  This  is 
perhaps  due  to  the  large  amount  of  sugar  in  the  tissues 
of  the  diabetic. 

When  infection  occurs  through  the  respiratory  tract,  the 
infection  usually  remains  localized  in  the  lungs,  but  the 
organs  adjacent  to  the  lungs  may  sooner  or  later  also  become 
involved.  General  infection  occurs  when  the  tubercular 
lesion  ruptures  into  a  bloodvessel. 

The  healthy  nasal  mucosa  appears  to  offer  considerable 
resistance  to  tubercular  infection.  The  tonsils  are  a  frequent 
portal  of  infection.  Tuberculosis  of  the  cervical  lymph- 
glands  may  have  its  origin  in  infection  through  the  tonsils. 
Pulmonary  tuberculosis  may  be  secondary  to  tubercular  cer- 
vical adenitis.  Kissing  a  tubercular  person  should  be 
refrained  from,  nor  should  a  tuberculous  individual  ever  be 
allowed  to  kiss  a  child.  This  interdiction  applies  to  the 
parents  and  members  of  the  family  as  well  as  to  strangers. 

Facial  tuberculosis,  or  lupus,  as  it  is  more  commonly  called, 
is  due  to  infection  with  the  tubercle  bacillus  through  the 
skin.  Infection  never  occurs  through  the  unbroken  skin, 
but  always  at  the  site  of  a  wound  or  an  injury.  Acne 
pimples  may  serve  as  an  infection  atrium.  The  surgeon  is 
extremely  liable  to  skin  infection.  Inoculation  at  autopsies 
has  also  been  reported.  These  anatoniic  tubercles  usually 
contain  very  few  bacilli.  The  subcutaneous  injection  of  dead 
tubercle  bacilli  results  in  the  formation  of  an  abscess. 

That  primary  infection  may  occur  through  the  gastro- 
intestinal tract  is  true.     This   may  follow  the    ingestion  of 


INFLUENCE  OF  HEREDITY.  195 

tubercular  food,  such  as  the  meat  of  tubercular  cattle,  or 
through  the  drinking  of  milk  containing  the  bacillus.  In- 
testinal tuberculosis  or  tuberculosis  of  the  mesenteric  and 
retroperitoneal  lymph-glands  is  seen  more  frequently  in 
infants  than  in  adults.  The  infection  may  occur  through  the 
mother's  milk,  or  through  cows'  milk  if  the  child  is  being 
raised  on  the  bottle.  The  large  number  of  cases  of  tabes 
mesenterica  in  children  confirm  this  statement.  Primary 
intestinal  tuberculosis  in  adults  is  not  so  common.  The 
infection  is  usually  a  secondary  one,  and  is  the  result  of 
the  swallowing  of  tubercular  sputum.  The  danger  of  infec- 
tion following  the  ingestion  of  tubercular  meat  is  not  nearly 
so  great  since  the  attention  of  the  public  has  been  called 
to  the  necessity  of  thoroughly  cooking  all  food.  Adults  are 
not  in  the  habit  of  consuming  large  quantities  of  milk,  nor 
are  they  obliged  to  depend  upon  milk  for  their  sustenance  as 
is  the  child.  This  fact  has  led  many  clinicians  to  make  the 
erroneous  statement  that  primary  intestinal  tuberculosis  is 
never  met  with  in  the  adult ;  that  it  is  always  secondary  to 
pulmonary  tuberculosis.  Yet  undoubted  cases  of  primary 
intestinal  tuberculosis  are  on  record. 

Milk  must  be  recognized  as  an  important  factor  in  the 
spread  of  tuberculosis,  and  the  oft-repeated  admonition  to 
sterilize  milk  before  using  is  not  without  reason.  If  a 
cow  is  tubercular,  no  matter  where  the  lesion  is  situated, 
whether  in  the  udder  or  elsewhere,  its  milk  is  very  liable  to 
contain  the  tubercle  bacillus.  A  tubercular  mother  should 
never  be  allowed  to  nurse  her  child,  and  when  the  child  is 
fed  on  cows'  milk  the  milk  should  always  be  rendered  sterile 
before  using.  From  the  intestinal  canal  the  infection  may 
spread  to  other  parts  of  the  body. 

Heredity  :  The  hereditary  transmission  of  tuberculosis  is 
still  a  matter  of  dispute.  A  few  cases  have  been  reported  in 
which  infection  took  place  through  the  placenta  ;  also  two 
cases  of  placental  tuberculosis.  These  findings  have  been 
confirmed  experimentally  in  animals.  It  is  extremely  doubt- 
ful that  infection  ever  occurs  from  the  father,  even  when  he 
is  suffering  from  tuberculosis  of  the  testicle  or  seminal  vesi- 
cles, although    he    may  infect  the  wife.     It  is  self-evident, 


196  BACILLUS  TUBERCULOSIS. 

however,  that  children  born  of  tubercular  parents,  or  of  a 
tubercular  father  or  mother,  are  predisposed  to  tuberculosis 
because  of  the  lack  of  sufficient  vitality  to  resist  that  or  any 
other  infection. 

Baumgarten  believes  that  the  disease  is  inherited  directly, 
but  that  the  great  vitality  of  the  tissues  of  the  developing 
child  inhibits  the  growth  of  the  tubercle  bacillus,  so  that  the 
germ  remains  latent  in  the  bone-marrow,  lymph-glands,  and 
other  parts  of  the  body  until  such  time  when,  either  through 
traumatism  or  disease,  the  natural  barriers  to  infection  are 
removed.  He  and  others  have  found  living  but  inactive 
tubercle  bacilli  in  the  organs  of  babies  born  of  tubercular 
mothers.  Gsertner  is  of  the  opinion  that  the  bacillus  is  not 
transmitted  to  the  foetus  by  the  mother,  but  that  during  par- 
turition the  bacillus  may,  in  consequence  of  tears  in  the  pla- 
centa, be  conveyed  to  the  child.  This  is  the  most  plausible 
explanation  of  those  infrequent  cases  of  primary  tuberculosis 
of  the  skin,  bones,  joints,  liver  and  other  organs,  which  occur 
in  young  children  who  present  no  other  evidence  of  tubercu- 
losis. 

Mixed  infection :  The  occurrence  of  mixed  infection  in 
tuberculosis  is  quite  common,  and  materially  lessens  the 
chances  of  recovery  from  the  original  infection.  This  is 
especially  true  in  pulmonary  tuberculosis  when  a  septicaemia 
is  added  to  the  tuberculosis.  The  organisms  which  are  most 
frequently  associated  with  the  tubercle  bacillus  are  the  strep- 
tococcus, staphylococcus,  MicrococGus  tetrageniis,  pneumococ- 
cus,  influenza  bacillus,  and  Bacillus  pyocyaneus. 

Demonstration  of  the  bacillus  :  Sputum  :  The  demonstration 
of  the  bacillus  in  the  tubercular  material  or  tissue  is  positive 
evidence  of  the  existence  of  the  disease.  Failure  to  find  the 
germ  in  stained  specimens  is  not  positive  evidence  of  the  non- 
existence of  the  disease.  It  should  be  borne  in  mind  that 
frequently,  especially  in  the  incipient  stages  of  tuberculosis 
repeated  examinations  must  be  made  before  it  is  possible  to 
find  the  organism.  It  is  always  well  to  make  five  or  six 
stained  specimens,  and  if  the  bacillus  is  not  found  in  these, 
several  more  should  be  prepared,  and  finally  the  microscopic 
finding  should  be  substantiated  by  the  injection  of  guinea-pigs. 


PLATE  V, 


Tubercle  bacilli  from  a  tubercular  cavity      Carbol-fuchsin, 
nitric  acid,  methyl-blue.    Zeiss  i/ig     O.  4.    (Senn.) 


DEMONSTRATION  OF  THE  BACILLUS.  197 

A  negation  should  always  be  withheld  until  every  possible 
means  of  finding  the  germ  has  been  exhausted.  A  -^^  inch 
oil-immersion  lens  should  be  used,  together  with  a  mechanical 
stage,  to  insure  examination  of  all  parts  of  the  specimen. 

The  sputum  is  collected  in  a  clean,  wide-mouthed,  glass- 
stoppered  bottle.  If  expectoration  is  very  scanty,  the  sputum 
should  be  collected  for  the  entire  twenty-four  hours,  other- 
wise the  sputum  expectorated  immediately  on  rising  in  the 
morning  is  taken.  The  sputum  should  be  examined  as  soon 
as  possible.  One  of  the  small  yellow  nodules  usually  con- 
tained in  tubercular  sputum  is  placed  on  a  clean  slide  or 
cover-glass  with  the  platinum  needle  or  with  forceps.  While 
selecting  these  nodules,  the  sputum  is  placed  on  a  black  back- 
ground to  facilitate  selection.  The  addition  of  a  small 
amount  of  carbolic  acid  to  the  sputum  will  coagulate  the 
albuminous  masses,  and  one  of  these  can  be  selected  for 
examination.  In  the  absence  of  nodules,  several  loopfuls  of 
the  sputum  are  placed  on  the  slide.  The  sputum  is  spread 
uniformly  and  as  thinly  as  possible,  dried  in  the  air,  fixed  in 
the  flame,  and  stained  in  accordance  with  any  of  the  methods 
detailed  in  the  chapter  on  staining.  In  order  to  obtain  the 
bacillus  free  from  associated  bacteria,  the  sputum  should  be 
washed  in  sterile  water  as  already  described. 

Feces :  A  flake  of  rectal  mucus  or  pus  is  examined  in  the 
same  manner  as  the  sputum.  It  is  exceedingly  difficult  to 
find  the  tubercle  bacillus  in  feces,  and  frequent  examinations 
are  necessary. 

Urine :  The  urine  is  first  centrifuged  or  allowed  to  settle, 
and  the  sediment  is  then  examined  for  tubercle  bacilli.  When 
present  they  usually  appear  in  bunches  or  masses.  The 
microscopic  examination  of  urine  or  any  other  fluid  rarely 
gives  positive  results  even  after  repeated  and  careful  centrifu- 
gation.  It  is  much  more  satisfactory  and  time-saving  to 
inject  the  suspected  material  into  a  guinea-pig  and  arrive  at  a 
diagnosis  in  that  way. 

The  bacillus  can  also  be  stained  in  sections  of  tissue.  The 
sections  are  prepared  in  the  manner  described  in  text-books 
on  histology,  and  are  stained  by  the  cold  method.  Decolorize, 
counterstain,  wash,  dehydrate,  and  mount  in  Canada  balsam. 


198  BACILLUS  TUBERCULOSIS. 

Milh  is  centrifuged  and  the  sediment  examined  for  the 
bacilli.  The  film  is  placed  first  in  chloroform  for  from  four 
to  six  minutes  in  order  to  extract  the  fat.  The  chloroform 
is  then  evaporated  over  the  flame,  and  the  preparation  is 
stained  and  mounted  in  the  usual  way. 

Animal  inoculation  may  often  have  to  be  resorted  to  in  the 
examination  of  tubercular  material  before  a  positive  diagnosis 
can  be  made.  Confirmatory  evidence  is  also  obtained  by  in- 
oculation of  animals. 


CHAPTEEIV. 

BACILLUS    TUBERCULOSIS   {Continued). 

Prophylaxis  against  tuberculosis :  In  view  of  the  bac- 
terial origin  of  tuberculosis,  it  may  not  be  amiss  to  say  a  few 
words  about  prophylaxis.  If  proper  disinfection  were  prac- 
tised, it  would  be  })ossible  to  stamp  out  effectually  the  disease 
by  simply  killing  all  the  tubercle  bacilli.  Prophylaxis  should 
be  directed  especially  against  the  sputum  as  the  most  common 
source  of  infection.  If  all  sputum  could  be  rendered  innocu- 
ous, tuberculosis  would  be  stamped  out  completely. 

The  patient  should  be  impressed  with  the  importance  of 
disposing  of  his  sputum  so  that  it  will  not  be  an  element  of 
danger  to  others.  In  hospitals  and  sanitoria  it  is  customary 
to  supply  the  patient  with  a  spit-cup  containing  either  water 
or  an  antiseptic  such  as  carbolic  acid.  If  the  sputum  is  kept 
wet,  it  cannot  desiccate  and  be  blown  about  the  room  every 
time  the  door  is  opened  or  by  the  draught  caused  by  women's 
skirts.  These  spit-cups  are  made  either  of  glass  or  porcelain. 
They  are  not  very  satisfactory,  however,  as  the  disinfectant 
action  of  the  carbolic  acid  is  not  very  great,  and  also  because 
of  the  coagulation  of  the  albumins  which  it  causes.  The 
contents  of  these  spit-cups  are  usually  emptied  into  a  water- 
closet  or  they  are  disinfected  by  boiling. 

A  much  better  spit-cup  is  the  one  in  use  by  the  Boston 
Board  of  Health.  It  consists  of  a  light  metal  frame  in 
which  a  pasteboard  box  is  placed.  When  the  cup  is  full,  or 
at  the  end  of  each  day,  it  is  removed,  and  burnt.  This 
insures  perfect  disinfection,  and  the  cups  are  so  inexpensive 
as  to  be  within  the  reach  of  everybody  (see  also  Fig.  19). 

On  the  street  the  tuberculous  individual  is  a  source  of 
greater  danger  than  in  the  house.  He  should  never  be  allowed 
to  expectorate  on  the  street,  nor  in  any  public  place  or  con- 

199 


200  BACILLUS  TUBERCULOSIS. 

veyance.  He  should  be  instructed  to  spit  into  a  piece  of  linen 
or  muslin,  or  an  old  handkerchief  or  a  Japanese  paper  nap- 
kin, which  is  burnt  at  the  first  opportunity.  The  patient 
may,  if  preferred,  carry  in  his  pocket  a  small  wide-mouthed 
flask,  stoppered  with  a  glass  or  other  impervious  stopper. 
The  flask  may  contain  water  or  an  antiseptic  fluid.  Dett- 
weiler's  spit-cup  is  especially  designed  for  that  purpose.  The 
patient  should  be  cautioned  against  swallowing  the  sputum. 

The  room  occupied  by  tubercular  patients  should  be  aired 
thoroughly  every  day,  and  vscrubbed  with  soap  and  water, 
followed  by  an  antiseptic  solution,  at  least  twice  a  week. 
The  room  should  contain  as  little  furniture  and  hangings  as 
possible.  Plenty  of  sunlight  should  be  admitted.  In  hos- 
pitals, asylums,  and  prisons  it  is  possible  to  isolate  the  tuber- 
cular patient.  Each  patient  should  have  his  own  set  of 
dishes,  and  anything  coming  in  contact  with  the  patient  or  his 
excreta  should  either  be  thoroughly  disinfected  or  destroyed 
by  burning.  After  his  demise  the  room  occupied  by  him 
should  be  disinfected  with  formalin  vapor. 

The  excreta  of  cases  of  intestinal  or  genito-urinary  tuber- 
culosis should  receive  the  same  care  as  the  sputum  in  pul- 
monary tuberculosis.  The  patient  should  not  be  allowed  to 
use  the  same  toilet  as  the  other  members  of  the  family.  The 
feces  and  urine  should  be  voided  into  vessels  containing  water, 
and  then  be  disinfected  with  lime,  or  formalin,  or  sulphate 
of  copper.  Sexual  intercourse  should  be  abstained  from 
entirely  by  persons  suffering  from  genito-urinary  tuberculosis. 

Notification  of  the  health  authorities  of  every  case  of  tuber- 
culosis would  do  much  to  prevent  spread  of  the  disease.  The 
cases  could  be  watched,  and  inspectors  could  visit  them  from 
time  to  time  and  instruct  them  in  the  principles  of  disinfec- 
tion so  far  as  pertains  to  the  individual  case. 

The  careful  inspection  of  cattle  carried  out  by  the  govern- 
ment has  made  infection  from  the  ingestion  of  tuberculous 
meat  or  milk  less  common  than  was  the  case  before  these 
preventive  measures  were  adopted.  In  fact,  the  only  positive 
safeguard  against  infection  through  meat  or  milk  is — never 
to  partake  of  any  meat  or  milk  unless  it  has  been  thoroughly 
cooked. 


IMMUNIZATION  AND  CUBE.  201 

Immunization  and  Cure. 

As  soon  as  it  was  learned  that  filtered  cnltures  of  the 
tnbercle  bacillus  contained  a  substance  which  was  capable 
of  producing  the  disease  in  animals,  various  attempts  were 
made  to  utilize  this  substance  for  the  production  of  immunity  to 
the  disease.  Up  to  the  present  time,  however,  all  attempts 
at  immunization  have  been  fruitless,  and  the  question  of 
immunization  against  tuberculosis  is  still  in  statu  quo.  Tlie 
blood -serum  of  animals  not  susceptible  to  tuberculosis,  and 
attenuated  and  sterilized  cultures  of  the  tubercle  bacillus, 
have  been  used  with  the  hope  of  producing  a  condition  of 
immunity,  but  without  success. 

Koch^s  researches  in  this  direction  have  been  most  valuable, 
and  may  in  the  course  of  time  be  productive  of  the  desired 
result.  He  found  that  the  remarkable  pathogenic  power  of 
the  tubercle  bacillus  was  due  to  a  toxin  produced  by  the  germ. 
Animals  were  injected  at  intervals  with  mixtures  contain- 
ing live  tubercle  bacilli,  with  the  result  that  the  condition 
produced  after  the  first  injection  disappeared.  The  same 
was  true  when  dead  bacilli  were  injected.  If  only  the  first 
injection  had  been  given,  the  animal  would  certainly  have 
succumbed,  but,  as  it  was,  some  of  them  remained  alive  for 
as  long  a  period  as  nineteen  weeks. 

A  50  per  cent,  glycerin  extract  of  tubercle  bacilli  cultures 
produced  the  same  result.  Koch  named  this  substance  tuber- 
culin. It  is  a  proteid  substance  which  is  insoluble  in  absolute 
alcohol,  and  resists  a  temperature  of  120°  C.  for  hours. 
Chemically  it  resembles  the  albumins. 

Healthy  animals  do  not  r^eact  to  subcutaneous  injections  of 
tuberculin,  even  as  much  as  2  c.c. ;  but  tubercular  animals 
succumb  very  rapidly  to  as  small  a  dose  as  0.6  c.c.  The 
injection  of  tubercular  animals  with  very  small  doses  of 
tuberculin  was  followed  by  improvement  in  the  general  con- 
dition, although  complete  recovery  rarely  occurred.  Injection 
into  diseased  animals  is  followed  by  a  febrile  reaction  which 
is  sufficiently  characteristic  to  be  of  diagnostic  value. 

Tuberculin  is  prepared  in  the  following  manner:  A  very 
wide  1000  c.c.  flask  is  half  filled  with  veal-bouillon  contain- 


202  BACILLUS  TUBERCULOSIS. 

ing  from  4  to  6  per  cent,  of  glycerin.  The  surface  of  the 
liquid  is  inoculated  with  a  pure  culture  of  the  tubercle  bacil- 
lus and  placed  in  an  incubator  for  from  six  to  eight  weeks, 
when  development  ceases.  The  thick  dry  pellicle  which  has 
formed  on  the  surface  of  the  liquid  sinks.  The  bouillon  is 
evaporated  over  a  water-bath  to  one-tenth  of  its  volume,  and 
filtered  through  porcelain,  gravel,  or  sterilized  filter-paper. 
The  filtrate  is  tuberculin.  It  contains  from  40  to  50  per 
cent,  of  glycerin  and  keeps  quite  well. 

Koch  believed  that  it  was  possible  to  produce  immunity 
against  the  toxin  but  not  against  the  bacillus.  Tuberculin  is 
not  bactericidal.  Tuberculin  induces  coagulation-necrosis  in 
the  vicinity  of  the  tubercular  lesion,  and  interferes  with  the 
further  development  of  the  bacilli,  many  of  them  dying.  The 
vitality  of  the  tissue-cells  surrounding  the  tubercular  spot  is 
also  seriously  diminished;  there  are  hypersemia  and  degener- 
ation of  the  tissue,  and  finally  absorption  of  the  poisons  into 
the  blood,  with  consequent  liability  of  spread  of  the  process 
to  other  parts  of  the  body. 

As  a  diagnostic  agent  tuberculin  is  of  great  value.  The 
subcutaneous  injection  of  tuberculin  in  doses  of  from  1  to  5 
milligrams  into  a  non-tubercular  individual  is  not  followed  by 
appreciable  reaction.  A  like  dose  injected  into  a  tubercular 
patient  is  always  followed  by  a  decided  reaction,  such  as 
increased  temperature,  headache,  lassitude,  and  at  times  nausea 
and  vomiting,  and  chilliness  or  distinct  chills  and  rigors.  In 
doubtful  cases  tuberculin  is  probably  the  only  means  at  our 
command  for  making  a  positive  diagnosis.  It  is  advisable  to 
begin  with  a  very  minute  dose,  in  order  to  ascertain  the  sus- 
ceptibility of  the  patient.  Subsequent  doses  can  be  regulated 
accordingly. 

Before  injection  the  temperature-standard  of  the  patient 
should  first  be  determined.  Therefore  the  temperature  is 
taken  every  two  hours  from  4  o'clock  in  the  morning  to 
10  o'clock  at  night,  for  two  or  three  days  prior  to  the  use  of 
the  tuberculin.  In  this  way  we  obtain  both  the  highest  and 
lowest  temperature-record  of  that  person,  and  this  tempera- 
ture-record is  a  valuable  aid  in  determining  the  degree  of 
reaction,  if  any. 


IMMUNIZATION  AND   CUBE.  203 

The  tuberculin  is  injected  subcutaneously,  either  into  the 
flank  or  between  the  shoulder-blades,  with  an  ordinary  hypo- 
dermic or  an  antitoxin  syringe,  both  the  instrument  and 
the  site  of  injection  having  first  been  rendered  sterile.  The 
reaction  usually  results  in  from  six  to  sixteen  hours ;  on  an 
average  in  about  twelve  hours.  It  is  advisable  to  give  the 
injection  at  midnight,  so  that  the  reaction  will  occur  at  a  time 
when  both  the  patient  and  the  attendant  are  wide  awake  and 
alert  to  note  any  change  in  the  patient's  condition.  The  re- 
action is  then  due  some  time  between  12  noon  and  4  o'clock 
in  the  afternoon. 

A  feeling  of  chilliness,  headache,  lassitude,  rise  in  tempera- 
ture, and  increase  in  the  pulse-rate  and  respiration,  sometimes 
nausea  and  vomiting,  constitute  the  reaction.  An  increase  of 
two  degrees  in  the  temperature  is  a  positive  indication  of  the 
presence  of  tuberculosis.  These  symptoms  usually  continue 
for  about  thirty  hours,  and  subside  gradually.  It  is  best  to 
begin  with  a  small  dose,  and  if  no  reaction  follows,  the  injec- 
tion may  be  repeated  with  a  larger  dose  at  intervals  of  three 
or  four  days  until  5  milligrams,  the  maximum  dose,  have 
been  administered.  If  no  reaction  occurs  then,  it  may  be 
accepted  as  positive  proof  that  tuberculosis  is  not  present. 

If  a  reaction  follows  the  injection,  the  same  result  cannot  be 
obtained  again  within  at  least  thir-ty  days.  This  has  been  used 
as  a  means  of  perpetrating  fraud  in  the  case  of  cattle  which 
are  known  to  be  tubercular.  They  are  injected  with  tuber- 
culin, and  if  another  examination  is  made  by  the  health 
authorities  within  the  next  thirty  days  their  finding  will  be 
negative. 

The  objection  has  been  raised  that  the  reaction  will  occur 
in  individuals  in  whom  the  tubercular  focus  or  foci  may  be 
encapsulated,  and  that  the  injection  would  under  these  cir- 
cumstances be  the  cause  of  active  manifestations  of  the  disease 
with  possibly  fatal  results.  This  objection  is  based  on  the 
fact  that  the  reaction  has  appeared  in  persons  who  exhibited 
absolutely  no  symptom  of  the  disease.  The  autopsy  on  such 
individuals  would  doubtless  disclose  tubercular  bronchial  or 
mediastinal  lymph-glands. 

Another  objection  is  that  the  tuberculin  may  contain  viru- 


204  BACILLUS  TUBERCULOSIS. 

lent  tubercle  bacilli,  and  that  the  disease  may  thus  be  produced 
in  persons  who,  up  to  tliat  time,  have  been  free  from  it.  The 
first-named  objection  is  given  considerable  credence  by  those 
whose  experience  in  the  use  of  tuberculin  lias  been  very 
limited.  Clinicians  who  have  used  tuberculin  as  a  diagnostic 
agent  very  freely  are  outspoken  in  their  opinion  that  it  never 
produces  disease  where  there  is  none,  nor  does  it  arouse  a 
latent  tuberculosis  into  fatal  activity.  As  to  the  second 
objection,  that  can  easily  be  overruled,  because  the  manufact- 
urers of  tuberculin  are  extremely  careful  in  its  preparation, 
testing  it  on  guinea-pigs  before  it  is  marketed.  Anders  has 
used  the  tuberculin-test  in  a  large  number  of  cases,  and  his 
experience  has  been  exceedingly  satisfactory.  The  same  is 
true  of  Wood,  who  had  charge  of  the  Cook  County  (Illinois) 
Consumptive  Hospital  for  many  years;  and  of  many  others. 

The  agglutination-test  has  also  been  used  as  a  diagnostic 
agent,  but  the  results  have  been  such  that  little  can  be  said  as 
to  its  value  in  diagnosis.  The  agglutination  of  the  bacilli 
occurs  neither  constantly  nor  regularly,  and  cannot  be  relied 
upon. 

"TR"  and  "TO":  After  a  further  study  of  tuberculin, 
Koch  came  to  the  conclusion  that  its  non-bactericidal  action 
was  due  to  the  very  tough  cell-membrane  of  the  bacillus, 
which  prevented  the  body  fluids  from  exerting  any  influence 
upon  it.  Neither  could  the  toxin  elaborated  by  the  bacillus 
be  carried  into  the  tissues  in  sufficient  quantity  to  cause  the 
formation  of  an  antitoxin.  Koch  then  conceived  the  idea  of 
breaking  up  the  bacillus,  either  mechanically  or  chemically. 
He  ground  up  the  dried  bacilli  very  finely  in  a  glass  mortar, 
and  then  made  a  watery  extract  of  the  soluble  parts  of  the 
germ.  The  operation  of  fragmenting  dried  bacilli  in  this  way 
is  attended  by  great  risks  to  the  operator  because  of  the  pos- 
sibility of  their  inhalation.  This  watery  extract  Avas  centri- 
fuged.  The  sediment  he  named  "TR^^  (tuberculin  residue), 
and  the  supernatant  clear  fluid  ^'TO"  (tuberculin  ober  or 
upper).  This  latter  was  found  to  contain  the  tuberculin,  but 
no  bacilli,  either  intact  or  fragmented. 

The  residue  contained  both  whole  and  fragmented  bacilli. 
With  this  preparation  Koch  was  able  to  produce  immunity  in 


BOVINE  TUBERCULOSIS.  205 

animals  to  virulent  bacilli.  But  his  experiments  lack  suffi- 
cient confirmation  to  warrant  their  repetition  in  man. 

Both  ^^TR"  and  '^TO"  are  preserved  in  20  per  cent, 
glycerin. 

Temporary  benefit  has  followed  the  use  of  TR  in  lupus. 

Some  striking  results  have  accrued  from  the  use  of  TR  as 
a  therapeutic  measure;  and  it  is  regarded  by  some  as  of  equal 
importance  with  hygiene  and  diet,  vvith  which  it  should 
invariably  be  combined.  Koch  says  that  tuberculin  is  of 
great  value  as  a  therapeutic  agent  in  early,  uncomplicated 
cases.  In  more  advanced  cases  it  is  necessary  to  wait  until 
the  temperature  becomes  normal.  The  treatment  should  be 
extended  over  considerable  periods,  with  intervals  of  from 
three  to  four  months,  until  the  injections  no  longer  give  any 
reaction.  The  consensus  of  opinion  seems  to  be  that  the 
various  sera  used  in  the  treatment  of  tuberculosis  are  of  value 
only  in  incipient  cases  and  when  used  in  conjunction  with 
other  measures.  They  are  all  powerless  to  remove  dead  tissue 
or  newly  formed  tubercular  tissue. 

Fisch  immunized  a  horse  with  TR  and  then  used  its  serum, 
which  he  called  antiphthisin.  He  has  used  this  serum  in  the 
treatment  of  tuberculosis,  and,  if  his  reports  are  reliable,  the 
results  have  been  good  in  each  case.  Klebs  used  antiphth- 
isin, but  failed  to  get  beneficial  results.  Antiphthisin  is 
really  a  very  dilute  tuberculin. 

Klebs  advocated  the  use  of  another  product  of  the  tubercle 
bacillus,  known  as  tuberculocidin,  which  in  the  hands  of  some 
clinicians  has  yielded  remarkably  good  results. 

Maragliano's  antitubercle  serum  is  obtained  from  horses 
immunized  to  tuberculosis  with  old  or  attenuated  cultures 
grown  in  glycerin-bouillon.  The  clinical  results  obtained 
with  these  sera  have  been  so  uncertain  that  it  is  impossible  to 
make  any  definite  statement  as  to  their  efficiency  or  utility. 

Bovine  Tuberculosis. 

Tuberculosis  in  cattle  is  of  special  interest,  because  the 
animal  is  one  of  the  sources,  and  an  important  one,  of  our 
food-supply. 


206  BACILLUS  TUBERCULOSIS. 

Although  it  has  been  known  since  Koch's  first  studies  in 
tuberculosis  that  there  was  a  slight  biologic  and  morphologic 
difference  between  the  bacillus  tuberculosis  of  man  and  that 
of  cattle,  yet  there  was  no  doubt  as  to  the  identity  of  these 
organisms. 

The  bacillus  of  bovine  tuberculosis  is  constant  in  its  shape  ; 
it  is  shorter  than  the  bacillus  of  human  tuberculosis,  and  does 
not  exhibit  the  variations  in  form  so  frequently  met  in  the 
human  variety.  It  stains  more  readily  and  evenly,  although 
occasionally  it  is  seen  to  contain  deeply  staining  bodies  sug- 
gestive of  spores.  It  has  been  demonstrated  experimentally 
that  it  is  much  more  virulent  than  the  bacillus  of  tubercu- 
losis in  man.  It  produces  extensive  lesions  and  induces 
rapid  coagulation-necrosis.  It  grows  more  slowly  in  culture. 
The  tissue  lesions  are  identical. 

Koch  recently  startled  the  medical  world  by  claiming  that 
the  bacillus  of  human  tuberculosis  and  the  bacillus  of  bovine 
tuberculosis  are  distinct  organisms,  and  that  reci])rocal  infec- 
tion never  occurs.  He  based  his  claim  on  the  finding  that 
injections  of  pure  cultures  of  human  tubercle  bacilli  into 
cattle  were  not  followed  by  a  typical  tuberculosis.  Although 
there  are  not  many  cases  on  record  where  tuberculosis  in  man 
can  be  traced  directly  to  cattle,  there  is  no  question  that  this 
occurs.  Cases  of  unquestionable  primary  intestinal  tuber- 
culosis, in  an  individual  who  is  not  tubercular,  cannot  be 
explained  in  any  other  way  than  by  assuming  that  the  germ 
was  ingested  with  the  food — i.  e.,  beef  Tabes  mesenterica  in 
artificially  fed  babies  undoubtedly  has  its  origin  in  the  milk- 
supply.  Until  more  accurate  studies  can  be  made  in  this 
direction  it  is  advisable  to  regard  bovine  and  human  tubercu- 
losis as  reciprocally  infectious  diseases. 

Fowl  Tuberculosis. 

The  bacillus  of  fowl  tuberculosis  is  morphologically  similar 
to  the  bacillus  of  human  tuberculosis.  It  is  long  and  slender, 
and  frequently  shows  branching  forms.  It  grows  quite  readily 
on  all  culture-media.  It  stains  like  the  bacillus  tuberculosis, 
but  takes  the  stain  more  readily.     Its  principal  distinctive 


PSEUDOTUBERCULOSIS.  207 

feature  is  that  it  grows  at  temperatures  which  are  fatal  to  the 
human  tubercle  bacillus.  This  diiference  may  be  explained 
by  the  fact  that  as  the  body  temperature  of  fowls  is  higher 
than  that  of  man,  the  germ  may  have  habituated  itself  to  the 
higher  temperature. 

Pseudotuberculosis. 

This  term  usually  has  reference  to  a  pathologic  condition, 
and  not  to  its  exciting  cause.  It  is  seen  in  animals,  and  is 
characterized  by  the  formation  of  small  nodules  resembling 
tubercles.  They  are  caused  by  inanimate  bodies,  animal 
parasites,  bacteria,  and  highly  organized  vegetable  parasites. 

Bacillus  pseudotuberculosis  is  a  short,  thick  rod,  which  does 
not  form  spores ;  stains  readily  with  the  anilin  dyes,  but  not 

Fig.  83. 


Smegma  bacilli,  similar  in  appearance  to  syphilis  bacilli.    X  1000.    (Park.) 

with  Gram's  solution.  It  does  not  liquefy  gelatin.  In  a 
gelatin  stab  it  grows  along  the  puncture  and  also  on  the  sur- 
face of  the  medium.  On  agar  a  heavy  gray  growth  develops. 
On  'potato  the  growth  is  luxuriant  and  of  a  yellowish  color. 
In  bouillon  the  growth  gradually  settles,  leaving  the  super- 
natant fluid  clear  and  transparent.  The  bacillus  is  pathogenic 
for  animals,  especially  mice,  rats,  and  guinea-pigs. 

Various  streptothrices  and  Aspergillus  glauciis  and  A.fumi- 
gatus  have  also  been  found  in  these  pseudotubercles. 


208  BACILLUS  TUBERCULOSIS. 

Bacillus  Smegmatis. 

This  bacillus  is  often  mistaken  for  Bacillus  tuberculosis. 
It  is  found  beneath  the  prepuce  of  man,  and  between  the 
labia  and  under  the  fourchette  of  woman.  In  appearance  it 
resembles  the  tubercle  bacillus  (Fig.  83),  stains  like  it,  and 
resists  the  mineral  acids,  but  is  decolorized  by  absolute  alcohol. 
It  is  non-pathogenic,  but  is  of  great  importance  in  diseases 
of  the  genito-urinary  organs,  when  it  mu.st  be  differentiated 
from  the  tubercle  bacillus.  Animal  inoculation  will  offer 
conclusive  evidence  as  to  its  identity. 


CHAPTEE    V. 

ORGANISMS   RESEMBLING  THE  BACILLUS 
TUBERCULOSIS. 

Bacillus  of  Leprosy. 

The  specific  cause  of  leprosy  is  the  bacillus  of  leprosy,  or 
the  lepra  bacillus,  discovered  by  Hansen  in  1879.  It  is 
always  found  within  the  leprous  tubercles,  contained  within 
the  cells,  and  is  also  found  in  the  blood  during  the  febrile 
attacks.  It  is  very  slender,  a  little  shorter  than  the  tubercle 
bacillus,  straight,  and  has  rounded  ends.  It  does  not  form 
spores,  but  in  the  stained  preparation  it  shows  unstained 
spaces,  just  like  the  tubercle  bacillus.  It  stains  readily  with 
aqueous  solutions  of  the  anilin  dyes,  but  retains  its  color 
when  treated  with  the  mineral  acids.  Gram's  method  is  also 
applicable.  It  is  not  motile,  and  always  occurs  singly  or  in 
groups  (Figs.  84-87). 

Various  attempts  have  been  made  to  cultivate  the  bacillus 
on  artificial  media,  but  the  results  have  been  extremely  unsat- 
isfactory. 

Thus  far  it  has  been  impossible  to  transmit  leprosy  to  ani- 
mals by  inoculation. 

Infection  in  man  usually  occurs  through  an  abrasion  of  the 
skin  or  the  nasal  mucous  membrane.  Infection  through  the 
respiratory  and  intestinal  tracts  has  never  been  known  to 
occur.  Sticker  believes  that  infection  always  occurs  through 
the  nose.  He  bases  this  opinion  on  the  facts — that  the 
nasal  lesion  is  the  only  constant  one  in  both  forms  of  lep- 
rosy (see  below) ;  that  the  symptoms  of  the  disease  always 
have  their  origin  in  the  nose ;  that  the  relapses  begin  with 
nasal  symptoms  ;  that  it  is  the  only  characteristic  lesion  ;  and 
that  the  bacilli  can  be  found  in  the  leprous  nodules  in  the 

14— Bact.  209 


210     ORGANTSMS  RESEMBLING  BACILLUS  TUBERCULOSIS. 


nose  long  before  they  can  be  demonstrated  in  any  other  part 
of  the  body. 

Varieties  of  leprosy  and  the  nodule :  The  characteristic  leprous 
nodule,  which  very  closely  resembles  a  tubercle  in  structure, 
is  usually  found  only  in  the  skin  and  subcutaneous  tissues ; 


Fig.  84. 


Fig.  85. 


1__             ,.  . 

•  < 

.J/ 

Fig.  86. 


Lepra  bacillus. 


but  may  in  exceptional  instances  occur  in  the  internal  organs, 
especially  the  spleen.  One  variety  of  leprosy  is  characterized 
by  extensive  ulceration  of  the  tubercles.  In  the  so-called 
ancesthetic  leprosy  the  bacilli  are  found  in  the  nerve  substance, 
in  the   spinal  cord,  and  in  the  brain.     They  have  also  been 


BACILLUS  OF  LEPROSY,  211 

found  enclosed  in  the  leucocytes  in  the  intestines,  lungs,  and 
in  the  sputum. 

The  leprous  nodule  or  tubercle  diiFers  from  the  genuine  tuber- 
cle in  that  it  is  vascular  and  contains  much  fibrous  tissue. 
The  bacillus  is  enclosed  within  large  cells,  which  have  been 
called  lepra-cells.  They  resemble  a  tubercular  giant  cell  in 
size,  but  are  not  always  multinucleated.  The  ulceration 
appears  to  be  due  rather  to  the  poor  vitality  of  the  tissue 
than  to  any  action  of  the  bacillus.  In  the  ancesthetic  form 
of  leprosy  the  nodules  are  located  on  the  peripheral  nerves, 
and  the  formation  of  fibrous  tissue  is  responsible  for  the  sub- 
sequent anaesthesia.  The  various  skin  lesions  occurring  in 
this  form  are  always  the  result  of  injury.  Burns  are  very 
common  because  of  the  annesthesia. 

Arning  inoculated  a  condemned  criminal,  who  was  perfectly 
healthy,  with  leprous  material,  and  in  five  years  the  disease 
was  fully  developed.  Other  attempts  to  infect  healthy  indi- 
viduals have  failed.  It  is  believed  that  leprosy  is  contagious 
in  the  same  sense  that  tuberculosis  is  contagious ;  and,  there- 
fore, that  contact  is  probably  not  so  much  a  source  of  infec- 
tion as  was  formerly  supposed. 

Baumgarten  is  of  the  opinion  that  it  is  also  inherited,  and 
cases  have  been  reported  in  which  that  assumption  seems  to 
be  the  only  explanation  for  the  occurrence  of  the  disease. 
Opposed  to  this  view  is  the  fact  that  leprosy  is  never  known 
to  occur  in  infants. 

Individual  susceptibility  is  an  important  factor.  Persons 
who  have  been  in  contact  with  lepers  for  years  have  not  con- 
tracted the  disease.  Sexual  intercourse  appears  to  be  a  very 
common  method  of  infection  in  leprosy. 

Diagnosis:  Preparations  made  from  the  serum  obtained 
from  a  leprous  nodule  are  stained  in  the  same  manner  as  for 
tubercle  bacilli.  The  lepra  bacillus  is  always  found  in  great 
numbers,  which  serves  to  differentiate  it  from  the  tubercle 
bacillus.  The  nasal  mucus  always  contains  lepra  bacilli.  The 
serum  of  a  leprous  patient  will  agglutinate  the  bacilli  in  dilu- 
tions of  1  :  60.  Leprous  patients  usually  die  from  exhaustion 
or  some  intercurrent  affection,  especially  inhalation  pneumonia. 

Distribution :  Although  leprosy  is  commonly  believed  to  be 


212     ORGANISMS  RESEMBLING  BACILLUS  TUBERCULOSIS. 

limited  to  certain  countries,  it  is  in  reality  comparatively 
widespread  in  all  parts  of  the  globe.  It  is  exceedingly  com- 
mon in  Egypt,  Syria,  China,  Siam,  Norway,  Sweden,  the 
Sandwich  Islands,  Turkey,  and  parts  of  Italy  and  the  United 
States,  and  India.  The  leper  colony  in  the  Sandwich  Islands 
contains  11,000  patients.  Isolated  cases  have  been  reported 
in  many  States  of  this  country,  especially  in  Louisiana,  where 
there  is  now  established  a  small  leper  colony.  Lepers  should 
be  promptly  isolated. 

Bacillus  of  Syphilis. 

In  1884  Lustgarten  discovered  a  bacillus  in  the  lesions  of 
syphilis  which  he  believed  to  be  the  specific  cause  of  the 
disease.  It  has  not  yet  been  accepted  as  the  cause  of  syphilis, 
and  for  that  reason  it  is  said  that  the  exciting  cause  of  syphilis 
is  unknown.  Lustgarten's  bacillus  resembles  the  tubercle 
and  smegma  bacilli.  Many  other  organisms  have  been  de- 
scribed as  causative,  but  Lustgarten's  is  the  only  one  which 
-is  deserving  of  consideration.  He  did  not  succeed  in  isolat- 
ing the  germ  and  cultivating  it,  nor  did  inoculation  experi- 
ments with  the  syphilitic  virus  produce  the  disease.  He 
based  his  claim  almost  entirely  on  the  constancy  of  the 
bacillus  in  the  lesions  and  discharges  of  syphilis.  It  stains 
in  a  very  peculiar  manner,  but  the  method  is  also  applicable 
to  the  tubercle  and  lepra  bacilli. 

Lustgarten's  bacillus  is  from  3  /i  to  5  /i  long,  and  from  0.2  /i 
to  0.3  /i  broad,  slightly  curved,  often  pointed  at  one  end,  and 
presenting  unstained  spaces  in  the  stained  specimen,  which  he 
believed  to  be  spores.  The  bacilli  usually  occur  singly  or  in 
groups  within  the  large  cells  (Fig.  88).  He  found  the  organ- 
ism in  all  the  lesions  of  syphilis,  both  internal  and  external. 

Preparations  are  made  from  the  tissues  and  the  discharges. 
The  film  is  fixed  by  passing  it  through  the  flame  only  once, 
and  is  then  kept  at  the  room  temperature  for  twenty-four 
hours.  It  is  stained  with  warmed  anilin-water  gentian- 
violet,  decolorized  in  absolute  alcohol,  and  exposed  to  the 
action  of  a  1.5  per  cent,  aqueous  solution  of  potassium  per- 
manganate for  ten  seconds.  A  second  decolorization  is  effected 


BACILLUS  OF  SYPHILIS.  213 

with  an  aqueous  solution  of  sulplmrous  acid.  Wash  in  water, 
return  to  the  permanganate  solution  for  a  few  seconds,  and 
then  place  in  the  sulphurous  acid  again  until  the  film  is  thor- 
oughly decolorized.  It  is  dehydrated  in  alcohol,  cleared  in 
oil  of  cloves,  and  mounted  in  Canada  balsam.  Nitric  acid 
readily  decolorizes  the  syphilis  bacillus,  but  not  the  tubercle 
or  lepra  bacilli. 

Van  Niesen  cultivated  a  bacillus  about  the  size  of  the 
tubercle  bacillus  from  the  blood  of  a  number  of  cases  of 
syphilis.  The  blood  is  obtained  by  puncture  from  the  finger, 
and  kept  in  a  sterile  dish  at  a  temperature  of  13°  to  15°  C. 


\ 


Fig.  88. 


\ 

Syphilis  bacilli  from  a  papule,  after  a  preparation  from  Lustgarten.    X  2500. 

for  ten  days.  It  is  then  ready  to  be  transplanted.  In  bouil- 
lon this  bacillus  produces  grayish-white  threads;  some  of  them 
forming  a  membrane  on  the  surface  and  others  floating  in  the 
medium.  In  a  gelatin  stroke  culture  it  forms  a  fine  grayish, 
streaky-looking  mass,  which  consists  of  threads,  some  of  which 
penetrate  into  the  medium.  The  gelatin  is  liquefied  v^ery 
slowly.  The  growth  on  agar  consists  of  a  central  grayish 
mass  with  projecting  rays.  Potato,  milk,  urine,  serum,  and 
water  are  also  available  as  culture-media. 

The  colonies  in  the  plate  culture  are  quite  characteristic, 
turning  from   gray  to  yellow,   and   finally  to  brown.     The 


214      ORGANISMS  RESEMBLING  BACILLUS  TUBERCULOSIS, 

organism  is  motile  and  forms  spores.  Later  it  changes  its 
form  to  a  coccus,  or  branched  forms,  or  it  may  resemble  a 
moukl.  It  stains  readily  with  the  anilin  dyes  and  with 
Gram's,  and  is  decolorized  by  the  mineral  acids. 

Inoculation  experiments  in  animals  produced  abortion  in 
pregnant  rabbits,  extragenital  primary  nodular  lesions  on  the 
ears,  secondary  ulcers  and  tumor  formations,  and  irregular 
lesions. 

A  white  diplococcus  has  also  been  found  and  successfully 
cultivated  on  agar  and  potato  from  the  blood  of  syphilitics. 
Perhaps  this  is  one  of  the  variations  of  Van  Niesen's  bacil- 
lus. 

Infection :  Infection  always  occurs  by  contact  with  the 
products  of  syphilitic  lesions  or  the  blood  of  syphilitics.  An 
abrasion  is  necessary  before  infection  occurs.  Sexual  inter- 
course is  the  most  frequent  method  of  infection,  although  the 
kissing  and  nursing  of  a  syphilitic  infant,  the  handling  of 
infected  instruments  and  other  objects,  the  depraved  habit  of 
tongue-sucking y  and  inoculation  of  the  fingers  of  physicians 
and  mid  wives  (extragenital  chancres)  by  coming  in  contact 
with  the  syphilitic  virus,  must  not  be  overlooked  as  equally 
dangerous,  and  by  no  means  infrequent,  methods  by  which 
infection  is  conveyed. 

The  primary  lesion  is  found  most  frequently  on  the  genitals, 
and  less  often  on  the  lips,  tongue,  tonsils,  nipples,  fingers,  etc. 
In  from  three  to  six  weeks  the  syphilitic  virus  is  disseminated 
throughout  the  entire  body,  and  then  the  so-called  secondaries 
appear.  Some  time  afterward  these  are  followed  by  the  lesions 
or  manifestations  of  the  tertiary  stage. 

In  hereditary  syphilis  the  portal  of  entrance  is  the  blood, 
and  here  the  primary  lesion  is  wanting,  the  secondaries 
inaugurating  the  attack.  Whatever  the  exciting  cause  of 
syphilis  may  be,  it  is  endowed  with  an  indefinite  term  of  life, 
and  the  disease  is  transmissible  throughout  this  entire  period. 

Immunity  :  Syphilis  is  the  one  disease  to  which  all  persons, 
all  races,  and  all  nationalities  are  susceptible.  There  is  no 
natural  immunity  to  syphilis,  but  one  attack  usually  confers 
immunity  against  another,  and  a  second  attack  is  a  rarity. 
Second  attacks  are   usually  relapses,  which   are   not  at  all 


BACILLUS  OF  SYPHILIS.  215 

uncommon  in  syphilis,  as  the  syphilis  germ  (?)  is  exceedingly 
tenacious. 

Colles  is  authority  for  the  statement  that  a  mother  giving 
birth  to  a  child  which  inherited  syphilis  from  the  father,  is 
herself  rendered  immune.  The  bacilli  apparently  do  not  pass 
from  the  foetus  to  the  mother,  but  the  toxins  do,  and  the 
immunity  is  conferred  in  that  way.  Such  a  mother  may  also 
nurse  her  infant  without  contracting  the  disease,  although  a 
wet-nurse  would  certainly  become  syphilitic  from  the  same 
source.  It  is  held  by  some  authorities  that  the  immunity  of 
the  mother  is  not  due  to  the  toxin  which  has  been  transmitted 
to  her  from  the  child,  but  that  she  may  herself  have  been 
inoculated  with  syphilis  by  the  husband.  All  attempts  to 
produce  immunity  in  non-syphilitics  by  injection  of  the  serum 
of  syphilitics  have  failed. 

Heredity  :  The  question  of  the  heredity  of  syphilis  presents 
some  interesting  points  which  may  now  be  discussed  profit- 
ably. It  is  a  well-known  fact  that  the  children  of  syphilitics 
are  either  born  with  evidences  of  syphilis  ;  or  they  do  not 
manifest  any  syphilitic  taint  at  birth,  but  show  evidences  of 
the  disease  later  on.  It  is  claimed  that  the  disease  is  trans- 
mitted from  the  father  through  the  spermatozoa.  Experi- 
ments tending  to  prove  this  assertion  have  been  unsuccessful, 
but  clinically  there  is  sufficient  evidence  at  hand  to  warrant 
the  statement  that  syphilitic  fathers  propagate  syphilitic 
children,  the  mothers  escaping  infection.  On  the  other  hand, 
it  is  held  that  in  the  absence  of  syphilis  in  the  mother  the 
child  will  remain  free  from  syphilis.  The  mother  may  not 
have  had  any  evidences  of  the  primary  ojr  secondary  lesions, 
but  well-marked  tertiary  symptoms  appear  later  on,  prov- 
ing that  the  mother  at  the  time  of  birth  of  the  child  really 
was  a  syphilitic,  and  that  her  healthy  condition  was  apparent 
only. 

The  opinions  of  eminent  syphilographers  are  divided  about 
equally  on  these  propositions  ;  but  if  the  second  is  true,  the 
first  is  unquestionably  untenable.  Furthermore,  the  children 
of  a  syphilitic  mother  are  always  syphilitic  even  when  syphi- 
lis in  the  father  can  be  ruled  out  absolutely.  Tlie  infection 
is  transmitted  through  the  ovum. 


2 1 6     ORGANISMS  RESEMBLING  BACILL US  TUBERCULOSIS. 

Infection  of  the  child  may  occur  during  its  intra-uterine 
life.  If  the  mother  is  infected  while  she  is  enceinte,  the  child 
is  also  infected,  except  when  infection  occurs  during  the  last 
two  months  of  pregnancy,  during  which  time  the  infection 
of  the  child  is  not  so  apt  to  occur.  The  mother  is  infected 
through  sexual  intercourse,  and  the  disease  is  carried  to  the 
foetus  through  the  placenta.  It  is  less  probable  that  the  foetus 
is  infected  first,  and  that  the  mother  is  infected  through  the 
foetus.  When  the  child  is  suffering  from  an  intra-uterine 
infection  the  primary  lesion  is  invariably  absent  at  birth.  If 
the  primary  lesion  makes  its  appearance  after  the  birth  of  the 
child,  the  infection  has  undoubtedly  occurred  extra-uterine. 


CHAPTEE    VI. 

GLANDERS    AND  ACTINOMYCOSIS. 

Bacillus  of  Glanders  (Bacillus  Mallei). 

The  specific  cause  of  glanders  is  the  Bacillus  mallei^  dis- 
covered by  Loeffler  and  Schuetz  in  1882,  in  the  lesions  and 
discharges  of  glanders. 

The  glanders  bacillus  is  a  small,  thick  rod,  with  rounded 
ends,  measuring  from  1.5  /i  to  3  fi  in  length,  and  from  0.2  fi 
to  4  /i  in  thickness.  It  is  not  motile,  has  no  demonstrable 
flagella,  and   is  without  definite   arrangement   or  grouping 

Fig.  89. 


Glanders  bacilli.    Agar  culture.    X  1000.    (Park.) 

(Fig.  89).     Some  observers  have  found  evidences  of  sporula- 
tion  and  others  have  not. 

It  stains  best  with  Loeffler's  methylene-blue.     It  is  very 
easily  decolorized.     Gram's  method  is  not  applicable.     The 

217 


218  GLANDERS  AND  ACTINOMYCOSIS. 

stained  specimen  appears  to  be  fragmented,  and  this  has  given 
rise  to  the  belief  that  it  produces  spores.  Bacillus  mallei  is  a 
facultative  anaerobe.  It  grows  readily  on  all  culture-media 
at  a  temperature  anywhere  between  25°  and  40°  C,  the 
optimum  being  37°  C. 

Vitality:  The  bacillus  is  killed  in  ten  minutes  by  exposure 
to  a  temperature  of  55°  C. ;  in  five  minutes  by  a  5  per  cent,  car- 
bolic acid  solution ;  in  two  minutes  by  a  1  :  5000  solution  of 
mercuric  chloride.  It  will  resist  drying  for  months.  The 
organism  does  not  thrive  as  a  saprophyte,  and  must  be  classed 
as  an  obligative  parasite. 

Pure  cultures  are  made  from  the  nasal  mucus  or  the  tissues 
of  animals  suffering  from  glanders.  A  very  rapid  method  is 
to  inject  the  suspected  material  into  the  peritoneal  cavity  of 
a  male  guinea-pig.  If  the  glanders  bacillus  is  present,  the 
testicles  will  be  involved  early.  They  break  down  and  fre- 
quently discharge  through  the  skin.  The  animal. is  killed, 
and  on  removing  the  testicles  the  tunica  vaginalis  is  found 
full  of  fluid  pus,  from  which  the  germ  is  obtained  in  pure 
culture.  It  will  grow  on  any  media,  but  best  on  glycerin- 
agar,  blood-serum,  and  potato. 

On  glycerin-agar  plates  it  forms  small,  glistening,  finely 
granular,  yellowish  colonies  within  forty-eight  hours.  In 
stroke  cultures  on  glycerin  agar  and  blood-serum  the  growth 
develops  along  the  entire  needle-track  as  a  very  thick  moist 
white  membrane.  Gelatin  is  slightly  liquefied.  Bouillon  is 
clouded. 

On  potato  the  growth  is  quite  characteristic.  It  first  forms 
a  luxuriant  moist  yellow  coating,  which  gradually  turns  to  a 
deep  reddish-brown.  The  potato  around  the  culture  takes  on 
a  greenish-yellow  tinge.  Milk  is  coagulated  with  the  pro- 
duction of  acid.  The  glanders  bacillus  loses  its  virulence  in 
culture,  but  regains  it  when  it  is  passed  through  animals. 

Pathogenesis  :  Glanders  is  primarily  only  a  disease  of  ani- 
mals, especially  the  lK)rse ;  but  man  is  extremely  liable  to  con- 
tract the  disease  from~infected  animals.  Cases  of  glanders 
have  also  been  reported  frequently  in  the  persons  of  laboratory 
assistants.  The  greatest  care  should  be  taken  in  the  handling 
of  this  or  any   other   pathogenic  organism.      The  glanders 


BACILLUS  OF  GLANDERS. 


219 


bacillus  produces  a  small  nodule  (Fig.  90),  which  somewhat 
resembles  the  tubercular  nodule,  and  which  finally  softens  and 
breaks  down.  The  bacillus  is  found  in  the  centre  of  the 
nodule. 

In  the  horse  the  disease  first  manifests  itself  by  the  forma- 
tion of  small  ulcers  on  the  nasal  mucous  membrane  and  an 
excessive  discharge  of  nasal  mucus.  The  submaxillary  and 
other  lymph-glands   soon   become   enlarged  and   suppurate. 

Fig.  90. 


^m^^ 


Bacilli  of  glanders :  a,  section  from  glandrous  nodule,  X  700 ;  b,  bacilli  of  glanders, 
stained  with  methyl-blue.    (Fluegge.) 


The  disease  may  extend  from  the  nose  to  other  parts  of  the 
body,  especially  the  lung. 

The  chronic  form  of  the  disease  which  affects  the  body 
generally  is  called /arc?/.  It  is  characterized  by  the  formation 
in  different  parts  of  the  body  of  small  circumscribed  swellings, 
known  as  farcy  buds.  These  finally  suppurate  and  form 
ulcers,  which  discharge  quite  freely. 

Infection  :  In  man  the  skin  is  the  most  frequent  portal  of 
entry  for  the  infection.  An  abrasion  is  always  necessary. 
Infection  may  also  occur  through  the  mucous  surfaces.  Cases 
are  on  record  where  hostlers  drank  from  the  same  pail  as  a 
horse  affected  with  glanders,  and  acquired  the  disease.     It  is 


220  GLANDERS  AND  ACTINOMYCOSIS. 

also  possible,  though  rather  infrequent,  that  infection  may 
occur  through  the  respiratory  and  gastro-iutestinal  tracts. 
The  organism  is  transported  in  the  body  through  the  lymph- 
vessels. 

In  man  the  disease  is  characterized  by  the  formation  of 
multiple  abscesses  in  the  skin,  muscles,  joints,  and  the  internal 
organs,  with  a  decided  tendency  to  a  fatal  ending.  The 
mucous  membranes,  especially  that  of  the  nose,  may  be  the 
seat  of  many  small  ulcers.  The  infection  resembles  a  strep- 
tococcus infection,  and  death  results  from  septicaemia.  The 
disease  may  be  transmitted  from  man  to  man  through  the 
secretions  and  the  excretions. 

Diagnosis :  The  methods  detailed  above  for  obtaining  the 
organism  for  culture  are  the  same  as  those  used  in  making  a 
diagnosis.     Animal  inoculation  is  by  far  the  most  reliable. 

The  organism  may  be  stained  in  tissue.  Loeffler  says  to 
place  the  section  in  a  solution  of  alkaline  methylene-blue  for 
five  minutes,  and  then  transfer  to  the  following  mixture  for 
five  seconds : 

Concentrated  sulphuric  acid,  2  drops ; 

5  per  cent,  solution  of  oxalic  acid,        1  drop; 
Distilled  water,  10  c.c. 

Dehydrate  in  absolute  alcohol,  clear  in  xylol  or  clove  oil,  and 
mount  in  Canada  balsam. 

Kuehne's  method  is  more  complicated.  He  places  the 
section  in  alkaline  methylene-blue  for  thirty  minutes;  washes 
well  in  water  and  decolorizes  in  a  weak  solution  of  hydro- 
chloric acid  ;  immerses  in  an  aqueous  solution  of  lithium  car- 
bonate (8  drops  of  the  saturated  solution  in  10  c.c.  of  water) ; 
washes  in  distilled  water ;  dips  in  absolute  alcohol,  slightly 
colored  with  methylene-blue,  for  a  few  seconds ;  dehydrates 
in  anilin  oil  containing  a  trace  of  methylene-blue  ;  washes  in 
pure  anilin  oil,  clears  in  xylol,  and  mounts  in  balsam. 

Immunity  and  Mallein :  One  attack  of  glanders  confers 
immunity  of  from  three  to  six  weeks'  duration.  It  has  thus 
far  been  impossible  to  produce  an  artificial  immunity.  3[alleln 
is  made  with  cultures  of  the  glanders  bacillus  just  like  Koch's 
original  tuberculin.     A  six-weeks-old  culture  of  the  glanders 


ACTINOMYCOSIS.  221 

bacillus,  grown  in  5  per  cent,  nutrient  glycerin-veal-bouillon, 
is  evaporated  to  one-tenth  its  volume.     The  result  is  mallein. 

It  is  very  largely  employed  as  a  diagnostic  agent.  The 
method  of  administration  and  the  reaction  in  positive  cases 
are  the  same  as  with  tuberculin.  In  an  animal  aifected  with 
glanders  there  usually  appears  at  the  site  of  inoculation  or 
injection  a  very  large  painful  swelling  accompanied  by  con- 
siderable inflammation  of  the  lymph-vessels  and  glands  and 
oedema.  This  reaction  persists  for  from  three  to  ten  days. 
In  animals  free  from  glanders  the  small  oedematous  tumors 
disappear  in  twenty-four  hours. 

Prophylaxis :  A  rigid  quarantine  should  be  instituted  in 
stables  in  which  glanders  is  found.  The  aifected  animals 
should  be  killed  immediately  and  the  carcass  destroyed  by 
fire.  The  attendants  should  be  warned  of  the  danger  of  con- 
tracting the  disease,  and  precautions  taken  to  prevent  infection 
from  spreading  to  the  other  stock. 

Actinomycosis  (Streptothrix  Actinomyces). 

Actinomycosis  is  a  disease  of  cattle,  but  is  occasionally 
seen  in  man. 

The  cause  of  this  peculiar  affection  is  the  actinomyces  or 
"ray  fungus."  Actinomycosis  is  no  longer  regarded  as  a 
mould  disease,  but  is  now  placed  in  the  same  class  "as  tuber- 
culosis. 

The  exciting  cause  is  not  a  mould,  but  a  streptothrix.  one 
of  the  higher  class  of  bacteria.  In  the  course  of  its  growth 
it  is  seen  to  assume  a  variety  of  forms,  sometimes  a  coccus,  or 
a  bacillus,  or  at  other  tirries  a  distinct  fungous  arrangement. 
Hektoen's  valuable  work  in  connection  with  the  study  of 
this  organism  has  enabled  us  to  make  a  proper  classification 
of  the  actinomyces. 

Although  the  infectious  character  of  the  disease  was  known 
as  early  as  1845,  it  was  not  until  many  years  later,  in  1877, 
that  the  specific  cause  was  discovered.  The  disease  was  first 
described  in  man  in  1885  by  Israel.  Four  years  later,  Bos- 
trom  succeeded  in  cultivating  the  actinomyces,  and  he  has 
given  a  very  detailed  account  of  his   work.     The  organism, 


222  GLANDERS  AND  ACTINOMYCOSIS. 

because  of  its  size,  is  easily  detected  in  the  lesions  as  small 
sulphur-yellow  granules  ranging  from  0.5  to  2  mm.  in  diame- 
ter. When  one  of  these  granules  is  transferred  to  a  slide 
and  examined  microscopically  (Fig.  91),  it  is  seen  to  be  made 
up  of  a  central  granular  mass  from  which  radiate  a  large 
number  of  club-shaped  threads.  It  really  consists  of  three 
zones :  the  central  granular  zone ;  next  to  that  a  zone  com- 
posed of  freely  interlacing  threads.  The  free  ends  of  these 
threads  are  directed  outward  to  form  the  third  or  outer  zone, 
which  consists  of  the  club-shaped  extremities  of  these  threads. 

Fig.  91. 


Three  actinomyces  from  a  case  of  pulmonary  actinomycosis.  Below,  three  finger-like 
buds  and  diehomatous  branching  of  actinomyces  threads.    X  450.    (Baumgarten.) 

It  is  easily  stained  with  the  usual  anilin  dyes,  and  also  by 
Gram's  method.  When  the  organism  is  to  be  stained  ih 
tissue,  picrocarmine  gives  very  good  results,  the  tissue  being 
stained  carmine  and  the  actinomyces  yellow.  Gram's  stain, 
followed  by  Weigert's  method  also  brings  out  the  organism  to 
good  advantage. 

Pure  cultures  are  made  from  the  actinomyces  granules. 
These  are  removed  from  the  tissues,  slightly  crushed  between 
sterile  glass  slides,  and  transferred  to  the  culture-medium. 
The  organism  is  strongly  aerobic,  developing  rapidly  at  the 
room  temperature  on  all  the  usual  media.  A  strictly  anaero- 
bic variety  has  also  been  described. 


ACTINOMYCOSIS.  223 

In  plate  culture  the  colonies  first  appear  as  very  small 
filamentous  grayish  masses.  On  blood-serum,  gelatin,  agar- 
agar,  and  glycerin-agar,  the  growth  develops  in  the  form  of 
small  yellowish  or  grayish  colonies,  which  soon  coalesce  to 
cover  the  entire  surface  of  the  medium  with  a  thick  dry 
wrinkled  fluffy  membrane,  which  adheres  to  the  media  very 
firmly.  It  is  utterly  impossible  to  remove  the  growth  with- 
out tearing  it  into  shreds.  Projecting  from  the  surface 
growth  down  into  the  medium  are  many  fine  threads.  Blood- 
serum  and  gelatin  are  liquefied.  The  surface  of  bouillon  is 
covered  by  a  membrane  just  like  that  on  the  solid  media,  but 
the  fluid  is  perfectly  clear.  Frequent  shaking  of  the  flask 
breaks  the  membrane  into  many  small  granular  masses. 

The  growth  on  potato  is  yellowish-red  in  color,  and  is 
covered  by  a  very  fine  white  fur.  The  actinomyces  grows 
quite  readily  in  both  raw  and  boiled  eggs.  It  is  introduced 
into  the  egg  through  a  small  opening  made  with  a  hot  needle. 
The  opening  can  be  sealed  with  collodion,  sealing-wax,  or 
paraffin.  Milk  is  peptonized.  In  all  stab  cultures  the  growth 
forms  on  the  surface  of  the  medium,  and  the  track  of  the 
needle  soon  becomes  filled  with  a  grayish  turbid  fluid.  The 
cultures  are  quite  resistant  to  drying.  They  are  killed  in  five 
minutes  by  a  temperature  of  75°  C. 

The  many  variations  of  this  organism,  or  what  might  be 
called  transition-stages,  can  readily  be  studied  in  the  cultures. 
There  are  long  wavy  filaments  of  uniform  size ;  short,  thick 
rods,  either  perfectly  straight  or  slightly  curved  like  the 
tubercle  bacillus  ;  filaments  with  segmented  ends  like  a  spore- 
containing  mycelium  in  the  thrush  mould  ;  many  micrococcus- 
like  bodies,  branching  forms,  rods  and  filaments  with  club- 
shaped  extremities,  all  of  which  must  be  considered  as  dis- 
tinct stages  in  the  development  of  this  remarkable  organism. 

Pathogenesis :  The  disease  is  common  in  cattle,  and  is 
usually  located  in  the  jaw,  where  it  forms  a  distinct  swelling. 
It  is  commonly  known  as  lumpy  jaw.  The  actinomyces  is 
ingested  with  the  food  (cereals),  and  then  finds  its  way  into 
the  jaw-bone  through  a  carious  tooth  or  an  injury  or  abrasion 
of  the  gum.  It  develops  rapidly,  forming  a  granulomatous 
tumor,  somewhat  similar  to  a  tubercle,  which  contains  many 


224  GLANDERS  AND  ACTINOMYCOSIS. 

small  round  cells,  giant  Cells,  and  leucocytes.  This  tumor 
eventually  undergoes  necrosis,  breaks  down,  and  discharges 
on  the  surface  through  a  sinus.  The  tumor  closely  resembles 
an  osteosarcoma  in  its  structure,  and  for  a  long  time  was  con- 
sidered as  such.  The  actinomycetes  are  found  imbedded  in 
this  tumor  mass. 

In  man  infection  may  occur  through  the  mouth,  through  the 
respiratory  or  gastro-intestmal  tract,  and  through  the  skin. 

Clinical  observation  of  the  disease  in  man  has  shown  that 
actinomycosis  not  infrequently  occurs  in  individuals  w^ho 
have  been  in  the  habit  of  chewing  wisps  of  hay  or  straw,  or 
different  kinds  of  cereals.  Certain  it  is  that  the  disease  is  seen 
only  in  persons  who  have  to  do  with  cattle  a  great  deal  and 
in  farmers.  In  many  instances  it  has  been  possible  to  prove 
the  existence  of  a  straw-chewing  habit.  People  who  are  in 
the  habit  of  chewing  a  tooth-pick  or  some  other  sharp-pointed 
or  rough  object  are  also  liable  to  the  infection  because  of  the 
presence  of  some  injury  of  the  gum  produced  by  the  foreign 
body  in  the  mouth.  The  lower  jaw  is  affected  more  often 
than  the  upper. 

Infection  through  the  sTdn  is  not  very  common.  It  always 
occurs  through  an- abrasion  or  a  wound.  Running  a  splinter 
of  wood  into  the  finger  or  foot  is  the  usual  method  of  infec- 
tion. 

Infection  through  the  respiratory  tract  occurs  as  a  rule  by 
inhalation,  although  the  disease  may  extend  from  the  jaw  along 
the  muscles  of  the  neck  and  into  the  lungs  and  pleura.  From 
there  it  may  continue  down  through  the  diaphragm  and  into 
the  abdominal  cavity.  When  the  disease  appears  in  distant 
parts  of  the  body  it  is  due  to  the  rupture  of  an  actinomycial 
mass  into  the  bloodvessels,  a  metastasis  such  as  is  seen  in 
malignant  tumors.  Lodgement  of  the  actinomyces  in  the 
lung  is  followed  by  a  fatal  bronchopneumonia. 

The  gafftro-intestinal  tract  serves  as  a  portal  of  infection 
when  food  containing  the  actinomyces  is  eaten.  The  inspec- 
tion of  cattle  is  very  stringent,  and  cases  of  lumpy  jaw  are 
always  promptly  condemned  ;  but  unfortunately  some  persons 
are  avaricious  enough  to  dispose  of  such  cattle  for  food,  and 
infection    from    that   source   is   possible.     The    disease   may 


STREPTOTHRIX  MADURJ^,  225 

appear  in  the  intestines  or  in  any  of  the  abdominal  viscera, 
especially  the  liver. 

Direct  transmission  from  cattle  to  man  has  not  been  demon- 
strated. 

Diagnosis :  The  microscopic  diagnosis  is  readily  made  by 
examining  the  little  sulphur-colored  granules  contained  in  the 
discharge  from  the  lesion  in  the  jaw ;  or  by  excising  a  portion 
of  the  tumor  and  either  making  sections  of  the  tissue  or 
crushing  a  small  piece  between  two  glass  slides. 

Streptothrix  Madurse;  Mycetoma  or  Madura  Foot. 

This  disease  is  peculiar  to  certain  parts  of  India  and  very 
closely  resembles  actinomycosis.  So  far  as  the  pathology  of 
the  two  conditions  is  concerned,  it  is  practically  identical. 

Many  investigators  are  of  the  opinion  that  the  streptothrix 
found  in  the  lesions  of  mycetoma  is  identical  with  Streptothrix 
actinomyces. 

Mycetoma  affects  usually  only  one  foot,  less  frequently  both, 
and  very  rarely  the  hand,  shoulder,  or  hip.  It  invariably 
follows  an  injury,  such  as  is  caused  by  stepping  on  a  nail, 
piece  of  wood,  or  a  thorn.  Small  nodules  or  tubercles  are 
formed,  which  later  attain  a  considerable  size,  break  down, 
and  discharge  freely.  The  discharge  is  either  purulent  or 
seropurulent,  and  contains  small  pinkish  granules,  Streptothrix 
madurse. 

Vincent  succeeded  in  cultivating  this  organism  on  acid 
vegetable  infusions,  which  are  apparently  most  suited  for  its 
growth.  It  is  a  strong  anaerobe.  A  surface  growth  develops 
on  liquid  media.  It  is  white  at  first,  but  soon  changes  to  a 
faint  red.  On  solid  media  small  round  colorless  colonies  are 
formed  which  do  not  coalesce.  Very  old  colonies  are  perfectly 
white.  The  growth  clings  to  the  medium  like  the  actinomyces. 
In  bouillon  the  growth  is  very  peculiar.  It  gradually  settles 
to  the  bottom  of  the  tube  and  has  the  appearance  of  a  small 
white  powder-puff  ball. 

The  growth  on  potato  is  very  meagre  unless  the  potato  has 
an  acid  reaction.  A  heavy  white  dry  woolly  membrane  is 
formed  which  never  changes  color. 

The  stained  specimen  very  closely   resembles    the  actino- 

15— Bact. 


226  GLANDERS  AND  ACTINOMYCOSIS. 

myces,  presenting  the  same  branched  forms,  clubs,  spore-like 
bodies,  and  filaments.  It  also  stains  like  the  actinomyces. 
Most  authorities  are  inclined  to  regard  the  Streptothrix  inadurce 
and  the  Streptothrix  actinomyces  as  separate  species,  but  there 
are  so  many  points  of  similarity  between  the  conditions  pro- 
duced by  them  that  one  is  justified  in  assuming  that  Strepto- 
thrix madurce  is  simply  a  variation  of  the  actinomyces,  such 
variation  being  due  to  conditions  which  influence  the  growth 
of  the  organism. 

Farcin  du  Boeuf ;  Streptothrix  Farcinse. 

This  is  another  disease  caused  by  an  organism  which 
resembles  the  actinomyces. 

The  exciting  cause  is  Streptothrix  farcinae  or  the  bacille  du 
farcin  des  boeufs  Noca7'd. 

The  disease  is  one  of  cattle,  and  is  never  seen  in  man. 
Pathologically  it  is  an  intense  inflammation  of  the  lymphatic 

Fig.  92. 


streptothrix  farcinae. 

structures,  especially  the  lymph-glands  in  the  axillae  and 
those  at  the  root  of  the  lung.  The  glands  are  considerably 
enlarged,  and  finally  break  down,  discharging  a  creamy  pus. 
The  specific  organism  is  found  in  the  centre  of  the  lesion. 
It  consists  of  very  long,  slender  filaments,  which  branch 
freely  and  contain  spore-like  bodies  (Fig.  92).  It  is  strongly 
aerobic,  and  grows  best  at  the  temperature  of  the  body.  It 
is  stained  by  Gram's  method,  and  also  with  the  ordinary 
anilin  dyes. 


RHINOSCLEROMA.  227 

On  agar-agar  the  growth  first  develops  as  small  very 
dry  discrete  irregular  masses  that  tend  to  become  confluent 
and  develop  a  yellow  color.  On  blood-serum  the  growth 
is  not  so  luxuriant  as  on  agar,  but  has  the  same  formation 
and  appearance.  Similar  appearing  masses  are  developed  in 
bouillon^  some  of  them  floating  on  the  surface  of  the  medium 
and  others  sinking  to  the  bottom.  Milk  is  not  coagulated, 
nor  is  its  reaction  changed.  On  potato  large  dry  scales  of  a 
pale-yellow  color  are  formed. 

Injection  into  animals  of  a  pure  culture  of  the  streptothrix 
produces  the  disease,  thus  positively  establishing  its  etiology. 
The  horse,  dog,  ass,  and  rabbit  are  immune.  Intraperitoneal 
injection  into  susceptible  animals  is  followed  by  extensive 
development  of  little  tubercles  in  the  omentum  and  the  peri- 
toneal covering  of  the  abdominal  viscera.  Intravenous 
injection  is  followed  by  the  development  of  tubercles  in  all 
parts  of  the  body,  resembling  an  acute  miliary  tuberculosis. 

Rhinoscleroma. 

This  disease  is  characterized  by  the  development  of  small 
circumscribed  tumors  on  the  nasal  mucous  membrane.  From 
this  point  the  disease  gradually  spreads  to  the  surrounding  tis- 
sues, sometimes  as  far  as  the  pharynx.  The  tumors  resemble 
the  lesions  of  glanders,  but  do  not  ulcerate. 

Von  Frisch  discovered  an  organism  in  the  lesions  which 
resembles  Friedlaender's  pneumobacillus  in  every  particular. 
It  is  surrounded  by  a  capsule,  stains  readily  by  Gram\s 
method,  and  is  always  found  within  the  tissue-cells.  It  grows 
readily  on  all  the  various  culture-media  and  induces  fermen- 
tation of  sugar.  Milk  is  coagulated.  It  has  been  impossible 
to  produce  the  disease  in  animals  by  inoculation. 


CHAPTEK    VII. 

BACILLUS  OF  TETANUS, 

Bacillus  tetani,  or  the  bacillus  of  Nicolaier^is  the  exciting 
cause  of  tetanus.  It  was  first  obtamecTTnipure  culture  by 
Kitasato,  in  1889,  but  was  discovered  by  Nicolaier  as  early 
as  1884.  It  is  the  accepted  cause  of  tetanus.  It  is  found  in 
the  purulent  discharge  of  tetanus,  at  the  site  of  inoculation ; 
in  the  soil,  especially  garden  earth  ;  and  in  the  excretions  of 
horses  and  cattle.     Its  appearance  is  very  characteristic. 

Biology  and  morphology :  It  is  a  very  slender  germ,  about 
the  size  of  a  small  red  blood-corpuscle,  from  3  to  5  /i  in  length, 

Fig.  93. 


Tetanus  bacilli  with  spores  in  distended  ends.    X  1100.    (Park.) 


with  an  enlargement  at  one  end  containing  a  spore,  the  typical 
drum-stick  shape  (Fig.  93).  When  the  bacterium  is  not  sporu- 
lating,  its  ends  are  rounded  and  it  is  regular  in  outline.  It 
has  no  flagella,  but  is  motile  nevertheless.  It  usually  occurs 
s[ngly,  rarely  forming  chains.  It  is  an  obligative  anaerobe, 
and  will  not  grow  in  the  presence  of  the  slightest  amount  of 

228 


VITALITY  OF  SPORES.     •  229 

oxygen.  That  is  one  reason  why  it  is  so  difficult  to  cultivate 
this  germ,  although  it  will  grow  on  all  kinds  of  culture-media. 
It  can  be  habituated  to  oxygen,  but  that  is  done  at  the  ex- 
pense of  its  virulence. 

It  grows  best  at  the  temperature  of  the  body.  It  is  readily 
stained  with  the  anilin  dyes,  and  also  by  Gram's  method. 
The  spores  are  stained  in  the  usual  manner.  When  the 
tetanus  bacillus  is  grown  at  very  high  temperatures  it  pre- 
sents distinct  involution-forms.  It  is  rapidly  destroyed  by 
temperatures  above^5°  C. 

The  bacillus  of  tetanus  is  grown  best  in  an  atmosphere  of 
hydrogen. 

On  gelatin  plates  small  white  colonies  develop  in  about 
five  days,  which  are  quite  characteristic.  They  have  the 
appearance  of  a  thistle,  very  fine  lines  radiating  from  a  dense 
central  mass.  The  gelatin  is  gradually  liquefied.  On  agar 
plates  the  colonies  develop  more  slowly ;  the  medium  is  not 
liquefied. 

In  gelatin  stab  cultures  development  occurs  along  the  line 
of  inoculation,  without  any  surface  growth,  in  the  form  of 
fine  radiating  threads  which  extend  from  the  central  line  of 
growth  out  into  the  gelatin,  an  appearance  which  suggests  a 
fir  tree  (Figs.  94  and  95).  This  characteristic  appearance  is 
lost  when  liquefaction  occurs  at  about  the  end  of  the  second 
week.  A  grayish-white  viscid  liquid  fills  the  centre  of  the 
medium,  and  the  culture  accumulates  at  the  bottom  of  the 
liquefied  mass.     Agar  cultures  are  not  liquefied. 

Plain  bouillon  or  glucose-bouillon  is  first  rendered  turbid, 
but  becomes  quite  clear  when  the  culture  settles.  The  super- 
natant fluid  contains  the  tetanus  toxin.  The  growth  in 
bouillon  is  accompanied  by  the  evolution  of  much  gas.  A 
very  disagreeable,  peculiar  odor  is  given  off  by  all  tetanus 
cultures. 

On  potato  a  moist  invisible  growth  develops.  3Iilk  is  not 
changed  in  appearance. 

Vitality  of  spores :  The  spores  are  quite  resistant,  and  will 
remain  alive  for  a  long  time.  When  exposed  to  live  steam  at 
a  temperature  of  100°  C,  they  are  killed  in  from  five  to  eight 
minutes.     A  much  longer  exposure  is  required  for  tempera- 


230 


BACILLUS  OF  TETANUS. 


tures  lower  than  this.  A  5  per  cent,  carbolic  acid  solution 
destroys  the  spore  in  about  fifteen  hours  ;  a  1  per  cent,  solution 
of  mercuric  chloride  in  about  three  hours.     The  addition  of 


Fig.  94. 


Fig.  95. 


Bacillus  tetani:  six-days-old  puncture 
ciilture  in  glucose-gelatin.  (Fraenkel  and 
Pfeiffer.) 


BaciUus  tetani :  culture  four  days 
old  in  glucose-gelatin.  (Fraenkel  and 
Pfeiflfer.) 


a  0.5  per  cent,  aqueous  solution  of  hydrochloric  acid  to  these 

antiseptics  hastens  the  destruction  of  the  spores  considerably. 

Kitasato's  method  for  isolating  the  bacillus  takes  advantage 

of  this  resistance  of  the  spores  to  high  temperatures. 


PA  THOGENESIS— INFECTION.  231 

tubes  are  inoculated  with  the  material  containing  the  tetanus 
bacillus  and  placed  in  the  incubator  for  two  days.  This  will 
cause  the  development  of  not  only'the  tetanus  bacillus,  but 
also  of  all  other  organisms  contained  in  the  culture.  This 
mixed  culture  is  heated  on  a  water-bath  at  a  temperature  of 
80°  C.  for  one  hour.  This  destroys  all  the  bacteria,  including 
the  tetanus  bacillus,  but  does  not  affect  the  spores  of  the  latter. 
Pure  cultures  are  made  from  this  spore-containing  culture 
according  to  the  methods  previously  described  for  the  cultiva- 
tion of  anaerobic  bacteria. 

Pathogenesis :  Man  and  nearly  all  the  domestic  animals, 
except  dogs  and  birds,  are  susceptible  to  tetanus.  The  infec- 
tion, in  order  to  become  manifest,  must  take  place  through  a 
wound.  The  organism  is  a  very  common  saprophyte  in  the 
soil,  and  cattle,  when  feeding  on  grass,  are  quite  liable  to 
swallow  the  germ,  which  passes  through  the  gastro-intestinal 
tract  without  exhibiting  any  evidence  of  infection.  The  fact 
that  the  tetanus  bacillus  is  so  frequently  found  in  manure 
proves  that  it  may  be  ingested  by  animals  without  producing 
the  disease.  It  grows  luxuriantly  in  jnanured  ground.  Teta- 
nus can  also  be  produced  artificially  by  injecting  the  germ 
into  the  circulation  or  into  the  peritoneal  or  other  cavities. 

Infection  :  The  most  frequent  partal  of  entry  of  the  germ  is 
through  the  skin.  Usually  the  site  of  infection  is  easily  recog- 
nized, but  occasionally  cases  of  tetanus  are  seen  in  which  it  is 
impossible  to  find  any  evidence  of  an  injury  which  may  have 
served  as  an  infection  atrium.  Penetrating  wounds  offer  the 
most  suitable  lodgement  for  the  bacillus.  Stepping  on  a  rusty 
nail  or  the  prongs  of  a  pitchfork  or  garden-rake  are  well- 
known  methods  of  infection  in  tetanus,  or  lock-jaw,  as  the 
disease  is  designated  by  the  laity.  It  was  at  one  time  believed 
that  tetanus  was  the  inevitable  result  of  such  an  injury.  The 
wound  may,  however,  be  produced  by  any  other  object  than 
those  mentioned.  Neither  is  it  essential  that  the  nail  or  ])roiig 
be  rusty,  although  the  danger  of  infection  in  that  case  is  much 
greater,  as  the  rusty  nail  has  lain  on  the  ground  for  some  time, 
and  is  more  liable  to  be  the  "  host ''  of  the  tetanus  bacillus 
than  a  clean  nail. 

The  wire  wrapped  around  baled  hay  is  also  responsible 


232  BACILLUS  OF  TETANUS. 

for  cases  of  tetanus.  Fish-bones,  wood,  and  any  object 
that  has  been  partially  buried  in  the  ground  for  some  time, 
may  convey  the  infection.  Many  cases  have  been  recorded 
from  localities  where  people  are  accustomed  to  bathe,  such  as 
sandy  beaches,  e.  g.,  the  shores  of  Long  Island,  where,  as  is 
known,  tetanus  has  followed  a  fish-bone  injury  of  the  foot. 

The  bites  of  insects,  such  as  the  sand  flea  or  the  chigger, 
may  be  instrumental  in  producing  tetanus.  This  is  particu- 
larly common  in  warm  countries,  where  the  inhabitants  are 
in  the  habit  of  going  barefoot.  Many  cases  were  reported 
from  Mexico,  when  the  soldiery  went  without  shoes  or  stock- 
ings, following  the  bites  of  the  chigger.  The  prick  of  a  pin 
is  sufficient  to  cause  infection.  All  that  is  necessary  is  a 
penetrating  wound  in  which  the  bacillus  can  develop  in  an 
oxygen-free  environment. 

Cases  of  tetanus  are  very  common  around  the  Fourth  of 
July,  and  usually  follow  an  injury  of  the  hand  produced  by 
the  explosion  of  a  fire-cracker  or  pistol.  Naturally  the  hand 
of  the  celebrant  is  not  very  clean  after  a  day's  shooting,  and 
all  the  accumulated  dirt  is  street-dirt,  which  may  contain  the 
tetanus  bacillus.  The  force  of  the  explosion  drives  this  grime 
into  the  wound  and  tetanus  results.  Superficial  wounds  or 
extensive  open  wounds  are  rarely  followed  by  tetanus,  because 
the  conditions  in  such  a  wound  are  unfavorable  for  the  devel- 
opment of  the  germ.  Penetrating  wounds  always  close  imme- 
diately after  the  instrument  inflicting  the  injury  is  withdrawn, 
thus  leaving  the  bacillus  in  the  bottom  of  the  wound  and  in  a 
most  favorable  environment.  The  bottom  of  the  wound  is  not 
exposed  to  the  air  and  the  germ  flourishes.  Sometimes  these 
wounds  close  so  tightly  that  it  is  impossible  to  locate  them 
even  within  a  few  hours  after  the  injury.  In  such  cases  the 
treatment  is  necessarily  more  difficult  than  when  the  wound 
can  be  located. 

If  the  infection  is  w^th  the  tetanus  germ  only,  very  little 
or  no  suppuration  occurs  ;  but  in  a  mixed  infection  suppuration 
is  always  "more  or  less  profuse.  Mixed  infections  are  always 
serious,  because  they  favor  the  development  of  the  tetanus 
bacillus.  The  aerobic  organisms  consume  the  oxygen  in 
the  wound,  and   the   tetanus  bacillus  is  furnished   with  an 


IMMUNITY.  233 

environment  in  which  it  can  grow  and  produce  its  toxin. 
Such  mixed  infections  probably  account  for  those  cases  where 
the  tetanus  does  not  manifest  itself  until  some  time  after  the 
injury  has  occurred.  The  bacilli  die  in  the  presence  of  oxy- 
gen, but  the  spores  survive,  although  they  remain  inactive 
until  such  time  when  conditions  are  favorable  for  their  devel- 
opment. If  the  infection  has  occurred  in  an  open  wound, 
the  disease  may  not  manifest  itself  until  after  the  wound  has 
closed. 

The  tetanus  bacillus  is  an  extremely  toxic  germ,  and  the 
manifestations  of  the  disease  are  entirely  due  to  absorption  of 
the  toxin. 

The  bacillus  does  not  spread  throughout  the  body,  but 
remains  confined  to  the  point  of  injury.  It  is  never  found 
in  the  tissues  of  the  body,  nor  in  the  blood  unless  injected 
experimentally,  ^o^  ^^  ^  milligram  of  a  filtered  culture 
is  sufficient  to  kill  a  mouse. 

A  man  weighing  175  pounds  would  be  killed  by  0.23  of 
a  milligram  of  tetanus  toxin. 

This  toxi7i  is  very  easily  destroyed  ;  and  its  chemical  com- 
position is  unknown. 

It  is  produced  in  large  quantities  by  the  bacillus,  and  its 
action  is  very  rapid. 

It  first  affects  the  muscles  nearest  to  the  point  of  infec- 
tion, and  then,  in  order,  all  the  parts  of  the  body.  Strychnine- 
poisonivg  resembles  tetaims  in  its  manifestations ;  and,  like 
strychnine,  the  tetanus  toxin  has  a  predilective  action  on  the 
spinal  cord.  The  action  of  the  tetanus  toxin  is  localized  in 
the  spinal  cord.  That  some  of  the  toxin  is  taken  up  by  the 
blood  and  lymph-currents  has  been  proved  by  injecting  blood 
from  a  case  of  tetanus  into  an  animal,  which  promptly  devel- 
oped the  disease.     The  toxin  is  excreted  by  the  kidneys. 

Immunity :  In  view  of  the  fact  that  the  bacillus  remains 
localized  at  the  site  of  infection,  and  that  the  circulating 
toxin  is  responsible  for  the  manifestations  of  the  disease, 
immunity  to  tetanus  must  be  against  the  toxin  and  not  the 
germ.  The  serum  of  animals  immunized  to  tetanus  confers 
immunity,  and  it  also  exerts  a  curative  action  ;  but  for  cura- 
tive purposes  a  larger  amount  of  serum,  or  a  more  active 


234  BACILLUS  OF  TETANUS. 

serum,  must  be  used.  Enough  serum  must  be  injected  to 
neutralize  the  toxin  in  the  body. 

The  toxin  is  prepared  from  active  bouillon  cultures,  which 
are  filtered  through  porcelain.  It  is  preserved  by  the  addi- 
tion of  0.5  per  cent,  of  carbolic  acid. 

The  antitoxin  is  prepared  by  inoculating  horses  with  gradu- 
ally increasing  doses  of  the  toxin  until  the  desired  degree  of 
immunity  is  attained.  The  method  of  preparation  of  anti- 
toxins has  been  described  in  a  preceding  chapter.  The  same 
product  is  used  for  immunization  and  for  therapeutic  pur- 
poses. 

This  serum  has  yielded  remarkably  good  results  as  an 
immunizing  agent;  but  not  as  a  therapeutic  measure.  The 
reason  for  this  is  evident  when  we  remember  that  unfortu- 
nately cases  of  tetanus  do  not  i)resent  themselves  for  treat- 
ment as  soon  as  the  injury  has  occurred.  The  patient  is  not 
seen  until  he  presents  the  active  manifestations  of  the  disease, 
and  then  it  is  impossible  to  administer  enough  antitoxin  to 
neutralize  all  the  toxin  which  is  already  in  circulation.  Per- 
sons should  present  themselves  for  treatment  as  soon  as  the 
injury  has  occurred,  so  that  prompt  measures  may  be  taken  to 
prevent  development  of  the  disease.  The  antitoxin  must  be 
used  early  and  in  sufficient  quantity  to  be  of  any  service  as  a 
curative  agent. 

Roux  and  others  have  suggested  that  the  antitoxin  be 
inj^ectejlunAer  the  _dura.  mater  through  a  trephine-opening. 
It  is  believed  that  if  the  antitoxin  is  brought  into  direct  con- 
tact with  the  cerebral  substance  a  cure  is  more  apt  to  result. 
Most  authorities  recommend  making  the  injection  directly 
into  a  vein j_  so  as  to  insure  prompt  action.  When  injected 
suEcutaneously,  the  antitoxin,  must  be  absorbed  first  and  thus 
the  action  is  delayed. 

Wassermann  is  of  the  opinion  that  it  is  possible  to  obtain 
an  immunizing  substance  from  the  nerve-cells  of  the  cord  and 
brain  of  cases  of  tetanus.  He  removed  the  brain  and  cord 
from  tetanized  animals  and  rubbed  them  up  with  physiologic 
salt  solution.  This  mixture  was  injected  into  animals,  and 
Wassermann  found  that  in  doses  of  1  c.c.  it  neutralized  ten 
times  the  amount  of  tetanus  toxin  necessary  to  kill  an  animal, 


PSEUDOTETANUS  BACILLUS.  235 

and  that  it  also  conferred  an  immunity  of  twenty-four  hours' 
duration. 

For  J/mmunizing  purposes,  the  dose  of  the  tetanus  anti- 
toxin is  J_0  c.c.  of  a  serum  of  the  strength  of  1  : 1,000,000,000. 
This  dose  may  be  repeated  in  a  week.  Yoy  tjwrapeidicj^]^ 
poseSj  the  initial  dose  should  be  ML  c.c. ;  and  depending  on 
the  severity  of  the  case,  from  20  to  50^c.c.  should  be  injected 
every  day  until  the  disease  is  under  control. 
^Sihce  this  antitoxin  has  been  used  the  number  of  fatal 
cases  of  tetanus  has  diminished  considerably,  although  the 
results  accruing  from  its  use  are  not  so  good  as  those  attained 
in  diphtheria  with  the  diphtheria  antitoxin.  Very  probably 
a  similarly  favorable  condition  of  affairs  would  obtain  if 
every  case  of  tetanus  could  be  treated  early,  before  the  germ 
has  developed  and  produced  sufficient  toxin  to  cause  active 
manifestations  of  the  disease. 

We  also  wish  to  call  attention  to  the  fact  that  treatment 
should  not  be  limited  to  the  use  of  antitoxin.  The  bacillus 
must  be  prevented  from  manufacturing  any  more  toxin. 
Surgical  intervention  is  absolutely  indicated.  Penetrating 
wounds  are  either  excised  completely  or  laid  widely  open,  so 
that  the  air  may  have  free  access,  and  thus  prevent  develop- 
ment of  the  germ.  The  cautery  and  strong  disinfecting  solu- 
tions should  also  be  used.  Every  effort  should  be  made  to 
prevent  formation  of  the  toxin,  to  prevent  its  absorption,  and 
to  neutralize  the  toxin  which  has  been  absorbed. 

Pseudotetanus  Bacillus. 

This  is  a  more  slender,  organism  than  the  tetanus  bacillus. 
It  is  club-shaped,  with  a  large  spore  in  one  end.  It  also  has 
flagella.  It  stains  with  the  anilin  dyes,  but  not  with  Gram. 
It  is  sometimes  found  in  large  numbers  in  the  appendix,  and 
was  considered  by  its  discoverer  to  be  the  cause  of  appendi- 
citis. It  does  not  resemble  the  tetanus  bacillus  in  culture. 
It  is  a  facultative  anaerobe. 


CHAPTER    VIII. 

BACILLUS  DIPHTHERIA,    OR   KLEBS-LOEFFLER 
BACILLUS. 

In  1883  Klebs  discovered  the  constant  presence  of  a  very 
peculiar  appeanng  organism  in  the  superficial  strata  or  layers 
of  the  pseudomembrane  removed  from  the  throats  of  patients 


Fig, 


Bacillus  diphtherias:  a,  its  morphology  on  glycerin-agar-agar ;  B,  its  morphology 
on  Loeffler's  blood-serum;  c,  its  morphology  on  acid  blood-serum  mixture. 
(Abbott.) 


suffering  from  diphtheria.     One  year  later  Loeffler  succeeded 
in  isolating  and  cultivating  this  same  orgaTvism,  and  it  has 

236 


BIOLOGY  AND   MORPHOLOGY.  237 

since  been  known  as  the  Klebs-Loeffler  bacillug.  Loeffler's 
findings  have  been  verifiecrby  others,  and  Bacillus  diphtherise 
has  been  accepted  as  the  specific  cause  of  diphtheritic  sore 
throat. 

The  bacillus  is  always  present  in  the  lesions  of  diphtheria, 
and  occasionally  is  found  in  the  healthy  throat  and  in  the 
throats  of  persons  who  have  recently  recovered  from  an  attack 

Fig.  97. 


Bacillus  diphtherise,  from  a  culture  upon  blood-serum.    X  1000. 
(Fraenkel  and  Pfeiffer.) 

of  diphtheria.  Abbott  cites  the  accidental  occurrence  of  diph- 
theria in  one  of  his  assistants  who  unintentionally  sucked  a 
few  drops  of  a  virulent  culture  of  the  diphtheria  bacillus 
through  a  defective  pipette,  thus  fulfilling  all  the  require- 
ments of  Koch's  law  as  to  the  specificity  of  any  s^erm. 

Biology  and  morphology :  The  diphtheria  bacillus  (Figs.  96 
and  97)  is  a  rather  thick  rod,  of  about  the  length  of  the  tubercle 
bacillus  and  with  a  marked  tendency  to  variation  in  form. 
The  rods  may  be  straight  or  slightly  curved  ;  of  a  uniform 
size   or    irregular;  pointed   at   one   end  and  clubbed  at  the 


238  BACILLUS  DIPHTHERIA. 

other;  of  a  d umb-bel  1  _s).Tape_  or  bulging  in  the  middle. 
Branching  forms  are  also  met  with  occasionally.  It  usually 
occurs  singly  and  rarely  forms  chains.  It  exhibits  a  slight 
tendency  to  parallelism.  It  has  been  suggested  that  there 
might  be  some  relationship  between  the  tubercle  bacillus,  the 
actinomyces,  and  the  diphtheria  bacillus,  because  all  three 
exhibit  the  same  variability  as  to  form  (Fig.  98). 

Bacillus  diphtherise  has  no  flagella  and  is  not  motile.  Spore- 
formation  has  not  been  observed.  It  is  easily  stained  with  the 
anilin  dyes,  but  best  with  Loeffler's  alkaline  methylene-bliie. 
Gram's  method  is. also  applicable.      It  does  not,  however, 

Fig.  98. 


Extremely  long  form  of  diphtheria  bacillus.    This  culture  has  grown  on  artificial 
rtiedia  for  four  years  and  produces  strong  toxin.    X  1100.    (Park.) 

stain  uniformly,  but  presents  spaces  suggestive  of  sporulation 
or  fragmentation  of  the  germ.  This  is  especially  marked  in 
the  larger  organisms.  Polar  bodies  are  common  in  the 
smaller,  more  regular  varieties.  They  are  the  Babes-Ernst 
bodies^  They  have  a  diameter  greater  than  that  of  the  bacil- 
lus and  give  rise  to  the  dumb-bell  shape.  These  irregularities 
in  staining  are  more  apparent  in  germs  which  are  cultivated 
artificially  than  in  those  obtained  directly  from  the  lesions. 
As  the  culture  ages  the  staining  becomes  less  characteristic. 
Neisser\s  stain  brings  out  the  polar  bodies  very  strongly. 
The  film  is  stained  for  two  or  three  minutes  in  the  following 
solution : 


BIOLOGY  AND  MORPHOLOGY.  239 

Alcohol  (96  per  cent.),  20  parts  ; 
Methylene-blue  (Gruebler),  1  part ; 

Distilled  water,  950  parts ; 

Glacial  acetic  acid,  50      " 

Wash  and  stain  with  the  following  for  from  three  to  five 
seconds : 

Bismarck-brown,  1  part; 

Boiling  distilled  water,  500  parts. 

This  is  followed  by  repeated  washings  in  water.  The  bacilli 
are  stained  dark  brown  with  a  dark-blue  body  at  one  or  both 
ends  (Fig.  99).      The   bacilli    taken  from    recent    cultures 

Fig.  99. 


Non-virulent  diphtheria  bacilli,  showing  stain  with  Neisser's  solutions,  supposed 
to  be  characteristic  of  virulent  bacilli.  Bodies  of  bacilli  in  smear,  faint  brown ; 
points,  dark  blue.     (Park.) 

invariably  show  this  polar  staining.     The  pseudobacilli  are 
stained  a  uniform  brown. 

The  germ  attains  its  maximum  development  at  the  temper- 
ature of  the  body.  It  is  a  facultative^  anaerobe.  One  marked 
cultural  characteristic  is  the  exceedingly  rapid  growth  on 
blood-serum.  The  diphtheria  colonies  appear  a  long  time 
before  those  of  any  other  organism.  A  growth  sufficient  for 
diagnostic  purposes  always  occurs  in  from  nine  to  twelve 
hours. 


240  BACILLUS  DIPHTHERIA. 

Loeffler^s  blood-serum  mixture,  consisting  of  3  parts  of 
blood-serum  and  1  part  of  1  per  cent,  glucose-bouillon,  is 
the  most  satisfactory  culture-medium  for  the  diphtheria  bacil- 
lus. This  is  the  medium  which  is  used  for  making  bacterio- 
logic  examinations  of  material  obtained  from  the  throats  of 
persons  suspected  of  having  diphtheria.  A  growth  is  present 
in  five  hours,  although  it  is  invisible.  The  colonies  are 
plainly  to  be  seen  nine  hours  after  inoculation  of  the  blood- 
serum.  They  appear  as  pearly-gray  or  yellowish-gray,  slightly 
raised  dots  with  irregular  borders  (Fig.  100),  steadily  increase 

Fig.  100. 


Colonies  of  diphtheria  bacilli.    X  200.    (Park.) 

in  size,  and  finally  become  confluent,  forming  a  nodular  yel- 
lowish-gray growth. 

On  agar-agar  and  glycerin-agar  development  occurs  more 
slowly  unless  the  culture  was  transplanted  from  blood-serum, 
when  development  takes  place  more  rapidly.  The  colonies 
are  large,  granular,  and  much  darker  in  the  centre  than  in 
the  periphery.  The  growth  may  be  so  luxuriant  as  to  resem- 
ble a  colony  of  a  staphylococcus. 

In  gelatin  stab  cultures  small  whitish  colonies  form  along 
the  line  of  inoculation,  with  a  slight  surface  growth.  The 
gelatin  is  not  liquefied. 


-      VITALITY-PATHOGENESIS.  241 

Bouillon  is  first  clouded,  and  then  the  growth  gradually 
accumulates  on  the  sides  and  bottom  of  the  tube  in  the  shape 
of  a  light  floeculent  precipitate,  leaving  the  bouillon  clear 
and  transparent.  Not  infrequently  the  surface  of  the  medium 
is  covered  by  a  very  thin,  fragile  membrane.  Picking  up 
the  tube  without  more  than  the  ordinary  agitation  caused 
thereby  causes  the  membrane  to  fall  to  pieces. 

On  alkaline  potato  a  delicate  surface  coating  is  formed. 
The  organism  growls  in  milk  without  changing  its  appearance. 
Litnmsjnilk  is  first  turned  a  faint  red,  and  then  blue  again. 
The  bacillus  grows  well  on  both  raw  and  boiled  eggs. 

Vitality :  A  striking  characteristic  of  the  diphtheria  bacil- 
lus is  its  very  feeble  resistance  to  heat  and  chemicals.  It 
is  destroyed  by  a  temperature  of  58°  C.  in  ten  minutes;  by 
1  :  lOOU  solution  of  bichloride  in  twenty  seconds,  and  as 
rapidly  by  5  per  cent,  solution  of  potassium  permanganate, 
5  per  cent,  carbolic  acid,  3  per  cent,  carbolic  acid  in  30  per 
cent,  alcohol,  and  4  per  cent,  cresol  in  40  per  cent,  alcohol. 
Pure  lemon  juice  is  rapidly  fatal.  It  cannot  withstand  dr^^- 
ing  for  any  length  of  time,  but  will  remain  alive  for  months 
if  enclosed  in  a  shred  of  the  diphtheritic  membrane.  It  is 
not  affected  by  cold. 

Pathogenesis :  The  diphtheria  bacillus  is  pathogenic  for 
man  as  well  as  animals,  especially  cats,  chickens,  and  pigeons. 
Animals  are  frequent  sources  of  infection,  particularly  when 
they  are  petted.  The  organism  gains  entrance  to  the  throat, 
and  when  conditions  are  favorable  for  its  development  it  pro- 
duces the  characteristic  pseudomembrane  of  diphtheria.  Other 
varieties  of  diphtheria,  as  well  as  chemicals,  not  infrequently 
are  the  cause  of  the  formation  of  a  pseudomembrane  in  the 
throat  which  cannot,  by  its  appearance,  be  differentiated  from 
the  diphtheritic  membrane.  This  membrane  usually  is  formed 
on  the  fauces  first,  but  may  appear  first  in  the  pharynx,  nares, 
larynx,  or  on  the  tonsils.  In  rare  instances  the  membrane 
may  be  formed  in  the  vagina  or  rectum,  on  the  conjunctiva, 
or  in  a  wound  of  the  skin.  This  membrane  has  a  dirty  white 
or  grayish  color  suggestive  of  decomposition,  and  when  it  is 
forcibly  detached  it  leaves  a  raw,  bleeding  surface. 

The  diphtheritic  infection^  like  tetanus,  is  purely  a  local  one. 

16— Bact. 


242  BACILLUS  BIPHTHERTjE. 

The  membrane  represents  the  local  reaction,  and  the  constitu- 
tional symptoms  are  due  to  absorption  of  the  toxin.  When 
the  germ  lodges  on  the  mucous  membrane,  it  excites  intense 
congestion  and  inflammation  in  the  upper  layers.  This  is 
followed  by  exudation  of  serum  into  these  layers  and  a  conse- 
quent lessened  nutrition  to  the  tissues.  This  lack  of  nutrition, 
together  with  the  toxin  elaborated  by  the  germ,  is  responsible 
for  the  coagulation-necrosis  which  follows,  and  represents  the 
final  step  in  the  process.  This  necrosed  tissue  is  the  so-called 
pseudomembrane  of  diphtheria.  There  is  no  deposit  on  the 
mucosa.  It  is  a  death  of  its  superficial  layers.  The  bacilli 
are  found  in  greatest  number  in  the  older  portions  of  the 
membrane.  From  the  original  site  of  infection  the  mem- 
brane gradually  spreads  to  other  parts  of  the  throat,  nares, 
and  larynx.  The  appearance  of  this  membrane  is  not  a 
criterion  of  the  toxicity  or  virulence  of  the  bacilli. 

The  toxin  elaborated  in  this  membrane  is  absorbed  by  the 
bloodvessels  and  lymphatics,  and  distributed  throughout  the 
body.  Its  entrance  into  the  circulation  is  marked  by  the 
appearance  of  constitutional  symptoms.  The  bacilli  are  rarely, 
if  ever,  found  in  the  blood. 

Diphtheria  is  seldom  a  pure  infection.  Associated  with 
the  diphtheria  bacillus  we  find  the  staphylococcus,  strepto- 
coccus, pneumococcus,  and  occasionally  Bacillus  coli  com- 
munis. These  associated  organisms  play  a  very  important 
role  in  diphtheria.  They  are  largely  responsible  for  the  com- 
plications of  diphtheria,  except  the  paralyses  which  are  due  to 
the  toxin,  and  for  those  severe,  aggravated  cases  which  resist 
all  treatment.  The  streptococcus  is  most  to  be  feared,  because, 
as  has  been  demonstrated  experimentally,  when  the  diphtheria 
bacillus  and  the  streptococcus  are  associated  the  latter  increases 
the  virulence  of  the  former. 

Infection:  The  disease  is  always  conveyed  from  one  per- 
son to  another  either  directly  or  indirectly.  Kissing  a  con- 
valescent is  a  common  source  of  infection.  The  bacillus 
has  been  found  in  the  throat  for  as  long  a  period  as  six 
months  after  subsidence  of  the  disease.  Persons  who  have 
come  in  contact  with  the  disease  may  not  themselves  be- 
come infected,  but  may  convey  the  disease  to  others.     The 


IMMUNIZATION  AND   THERAPY.  243 

patient's  toys,  eating  utensils,  dishes,  clothing,  or  bed-linen 
may  convey  the  disease.  The  infecting  agent  is  the  small 
pieces  of  membrane  coughed  up  by  the  patient.  They  may 
be  so  small  as  to  be  invisible,  and  when  they  lodge  on 
the  clothing  of  the  nurse  or  physician,  or  on  the  furniture 
or  hano-ings  in  the  room,  they  escape  notice.  When  the 
patient  sneezes  or  coughs,  a  cloth  saturated  with  bichloride 
should  be  held  before  the  face.  Infection  from  this  source 
should  be  guarded  against  very  carefully. 

It  is  very  unwise,  as  well  as  dangerous,  for  the  physician, 
when  examining  the  throat,  to  stand  directly  before  the  patient. 
The  examination  usually  induces  a  coughing  spell  or  gagging 
severe  enough  to  detach  small  pieces  of  membrane,  which 
lodge  on  the  clothing,  hair,  or  beard  of  the  physician.  He 
may  escape  the  infection,  but  he  serves  as  a  walking  incubator, 
and  any  one  coming  in  contact  with  him  may  become  infected. 

It  should  be  borne  in  mind  that  in  many  cases  of  diphtheria 
the  throat  manifestations  are  very  mild,  and  the  disease  may 
not  be  suspected.  For  this  reason  it  is  advisable  to  regard 
all  cases  of  angina  with  suspicion  until  their  identity  has  been 
established.  It  has  been  suggested  that  the  infection  may  be 
conveyed  through  milk,  although  that  mode  would  seem  rather 
im})robable  unless  a  piece  of  membrane  was  accidentally  de- 
posited in  the  milk. 

Cats  may  be  a  frequent  source  of  infection.  Their  wan- 
dering propensities  predispose  them  to  infection  from  any 
case  in  the  vicinity,  and  when  a  child  plays  with  the  cat  it 
may  contract  the  disease.  During  di})htheria  epidemics,  or 
when  cases  are  known  to  exist  in  the  immediate  neighborhood, 
it  is  well  to  watch  these  household  pets  carefully,  and  chil- 
dren should  not  be  allowed  to  play  with  them. 

The  toxin  of  the  diphtheria  bacillus  is  intensely  poisonous. 
A  toxalbumin  has  also  been  isolated.  The  chemical  compo- 
sition of  the  toxin  is  unknown.  It  is  obtained  by  filtering 
bouillon  cultures  through  a  porcelain  filter.  It  is  destroyed 
in  five  minutes  by  boiling.  When  kept  in  a  cold  dark  place 
it  retains  its  toxicity  for  years. 

Immunization  and  therapy  :  Behring  was  the  first  to  dis- 
cover that  the  blood-serum  of  animals  immunized  to  diph- 


244  BACILLUS  DIPHTHERIA. 

theria  contains  a  substance  which  neutralizes  the  effects  of  the 
diphtheria  bacillus  and  its  toxin.  Intensely  virulent  bacilli 
are  grown  in  alkaline  bouillon  in  the  incubator  for  five  to 
seven  days  until  the  medium  is  strongly  alkaline.  A  0.4  per 
cent,  solution  of  trikresol  is  then  added  and  the  mixture  filt- 
ered through  porcelain.  The  filtrate  contains  the  toxin, 
which  is  used  for  immunizing  purposes. 

One  attack  of  diphtheria  confers  immunity,  which  is,  how- 
ever, of  only  temporary  duration.  If  it  is  desired  to  immun- 
ize persons  who  have  been  exposed  to  the  disease,  only  a 
small  amount  of  the  antitoxin  is  injected.  Five  hundred 
units  will  confer  protective  immunity  for  about  six  wrecks. 
This  injection  should  be  made  as  promptly  as  possible,  as  it 
will  otherwise  fail  of  producing  the  desired  result.  For 
therapeutic  purposes  a  larger  amount- — that  is,  a  stronger 
serum — must  be  used. 

The  antitoxin  treatment  of  diphtheria  is  an  absolute  specific, 
and  when  used  properly  never  fails  to  give  the  results  which 
are  claimed  for  it.  Notwithstanding  the  opinion  of  those  who 
are  still  prejudiced  against  it,  the  antitoxin  should  be  used  in 
every  case  of  diphtheria.  Its  use  is  never  followed  by 
untoward  results.  The  reported  results  which  ostensibly 
contraindicate  the  use  of  antitoxin  are  entirely  due  to  faulty 
administration  and  to  its  being  used  too  late.  It  may  be 
well  to  refer  briefly  to  its  correct  use. 

Use  of  antitoxin  :  Most  important  of  all  is  that  it  should 
be  used  early  ;  and,  second,  in  sufficient,  strength.^  Although 
only  a  sliort  time  is  required  for  making  a  bacteriologic  diag- 
nosis, it  is  better,  in  order  to  be  on  the  safe  side,  to  use  the 
serum  at  once  if  diphtheria  is  suspected.  Even  if  the  micro- 
scopic diagnosis  negatives  diphtheria,  the  injection  of  serum 
will  not  have  done  any  harm.  The  most  common  mistake 
made  in  using  the  serum  is  in  w^aiting  until  the  medicinal 
treatment  has  failed  before  the  serum  injection  is  made.  Too 
many  practitioners  look  upon  antitoxin  as  a  last  resort,  and 
when  used  as  such  it  proves  ineffectual.  In  severe  cases  of 
diphtheria  death  usually  results  ;  but  if  the  serum  has  been 
used,  it  is  sure  to  be  blamed  for  the  fatal  outcome.  Perhaps  the 
case  would  have  been  saved  if  the  serum  had  been  used  in  time. 


USE  OF  ANTITOXIN.  245 

The  most  thorough  antisepsis  should  obtain  when  the 
serum  is  injected.  Many  of  the  unsatisfactory  results  follow- 
ing injection  can  be  ascribed  to  a  careless  injection.  Abscesses 
may  develop  at  the  site  of  the  injection  and  death  may  follow 
from  septicaemia  or  even  pyaemia.  These  are  the  cases  that 
are  '^  made  worse  ^'  by  the  injection.  A  hypodermic  injection 
should  always  be  looked  upon  as  a  surgical  procedure,  and 
the  strictest  asepsis  carried  out. 

The  injection  can  be  made  into  the  buttock  or  the  loose 
tissues  of  the  abdomen,  but  the  best  place  is  the  subcutaneous 
tissue  of  the  back  between  the  shoulder-blades.  The  patient 
should  be  held  absolutely  quiet  during  the  injection.  The 
child  can  be  wrapped  in  a  sheet  or  cloth,  and  held  by  the 
assistant  in  such  a  manner  that  only  the  back  of  the  patient 
is  exposed.  The  instruments,  hands  of  the  operator,  and  the 
site  of  inoculation  are  rendered  sterile.  The  smallest  quan- 
tity of  antitoxin,  consistent  with  the  dose  it  is  desired  to 
inject,  should  be  used.  The  injection  should  be  made  slowly 
and  the  needle  withdrawn  gradually,  the  skin  at  the  punct- 
ure being  held  firmly  between  the  first  finger  and  thumb 
of  the  left  hand.  By  gently  manipulating  the  tissues  absorp- 
tion of  the  antitoxin  will  be  facilitated  considerably.  The 
wound  is  sealed  with  collodion  and  covered  with  a  protective 
dressing.  It  is  useless  to  give  the  antitoxin  by  mouth, 
because  it  is  digested  in  the  alimentary  canal  without  exhibit- 
ing any  action. 

No  matter  what  the  age  of  the  patient,  the  initial  dose 
should  be  from  1500  to  2000  units.  In  very  severe  cases  at 
least  3000  units'~should  be  used.  If  the  reaction  does  not 
occur  within  twenty-four  hours  after  the  injection  is  made, 
another  1000  units  should  be  injected.  This  may  be  repeated, 
if  necessary,  on  the  following  day.  It  is  a  matter  of  record 
that  since  the  advent  of  the  antitoxin  treatment  of  diphtheria 
the  mortality  from  this  disease  has  been  reduced  at  least  one- 
half;  and  in  the  hands  of  some  clinicians  the  percentage  of 
fatalities  is  even  less.  The  necessity  for  intubation  or  trache- 
otomy has  been  correspondingly  diminished ;  and  in  cases  in 
which  these  procedures  have  been  performed  the  mortality  is 
less  now  than  what  it  was  when  the  antitoxin  was  not  used. 


246  BACILLUS  DIPHTHERIM. 

The  observation  has  been  made  that  paralysis  occurs  more 
often  after  the  use  of  antitoxin  than  when  it  is  not  used. 
McFarland  has  studied  this  subject  very  carefully,  and  arrives 
at  the  conclusion  that  this  is  to  be  expected,  as  these  palsies 
usually  follow  very  severe  cases,  and  that  they  would  have 
occurred  anyway  no  matter  whether  or  not  the  antitoxin  was 
used ;  so  that  the  antitoxin  is  not  responsible  for  the  paraly- 
ses. Furthermore,  he  says  that  these  cases  were  so  severe 
that  they  would  not  have  recovered  even  if  the  antitoxin  had 
not  been  used.  In  cases  in  which  a  large  amount  of  toxin 
has  been  elaborated  and  absorbed,  the  antitoxin  is  not  able  to 
neutralize  all  the  toxin,  and  the  result  is  nil;  but  when  used 
in  sufficient  quantity  it  never  fails  to  produce  the  expected 
results. 

If  small  quantities  of  a  high  grade  of  antitoxin  are  used, 
the  skin  rashes  which  occasionally  follow  the  administration 
of  antitoxin  are  not  so  apt  to  occur  as  when  large  quantities 
of  an  antitoxin  having  a  low  degree  of  immunizing  power 
are  used.  These  skin  rashes  are  of  no  significance,  however, 
so  far  as  the  course  of  the  disease  is  concerned ;  but  they 
may  be  exceedingly  annoying,  as,  for  instance,  an  extensive 
urticaria. 

Bacteriologic  diagnosis :  A  bacteriologic  diagnosis  should  be 
made  as  soon  as  the  case  is  seen.  For  the  sake  of  conve- 
nience, special  diphtheria  diagnosis  outfits  are  put  up  by 
nearly  all  boards  of  health.  Each  outfit  comprises  a  small 
platinum  box,  containing  blood-serum,  which  is  sealed  with  a 
heavy  rubber  band  to  prevent  evaporation  of  the  medium  ; 
and  a  swab  or  inoculator  consisting  of  a  small  iron  rod 
or  wooden  stick,  one  end  of  which  is  wound  with  cotton. 
This  inoculator  is  absolutely  sterile,  and  is  enclosed  in  a 
sterile  glass  tube.  A  wooden  tongue-depressor  completes  the 
outfit,  which  is  placed  in  a  heavy  Manilla  envelope.  The 
latter  may  be  opened  conveniently  without  destroying  it,  and 
on  the  outside  is  stamped  the  date  after  which  it  is  no  longer 
advisable  to  use  the  culture-medium. 

A  small  portion  of  the  membrane  is  removed  from  the 
throat  with  the  inoculator  and  transferred  to  the  culture- 
medium.     If  no  membrane  is  visible,  the  inoculator  should 


PSEUDODIPHTHERIA   BACILLUS.  247 

be  thoroughly  but  gently  rubbed  over  the  inflamed  mucous 
membrane  of  the  fauces  and  a  smear  made  on  the  blood- 
serum.  The  tongue-depressor  is  burnt  immediately  after  it 
has  been  used,  likewise  the  swab.  The  platinum  box  is 
sealed  with  the  rubber  and  placed  in  the  incubator  for  from 
nine  to  twelve  hours,  when  the  surface  of  the  blood-serum  is 
seen  to  be  studded  with  a  number  of  small  white  translucent 
colonies,  from  which  a  slide  is  prepared. 

As  most  physicians  do  not  possess  an  incubator,  it  will 
suffice  to  carry  the  box  containing  the  culture  in  the  waist- 
coat pocket  or  as  near  the  body  as  possible ;  or  it  can  be 
placed  in  the  axilla  and  strapped  there.  This  makes  an 
efficient  incubator.  If  the  inoculation  is  made  at  night, 
the  box  can  be  placed  in  the  pocket  of  the  night-gown. 
In  the  morning  the  culture  will  have  developed  sufficiently 
to  be  examined.  Ohlmacher  says  that  sufficient  growth  has 
taken  place  at  the  end  of  five  hours  to  permit  of  a  diagnosis. 
The  growth  is  not  visible,  but  if  a  sterile  platinum  needle  is 
carefully  rubbed  over  the  surface  of  the  blood-serum  and 
mixed  with  a  drop  of  sterile  water  on  a  slide,  the  diphtheria 
bacilli  will  be  found  in  the  stained  specimen. 

A  diagnosis  can  also  frequently  be  made  by  examining  a 
stained  piece  of  membrane.  It  is  not  necessary  to  tear  off  a 
large  piece  of  membrane.  The  bacteria  are  in  the  superficial 
layer,  and  a  little  scraping  of  membrane  will  suffice  for 
examination.  In  an  emergency  a  piece  of  membrane  can  be 
well  wrapped  in  a  cloth  and  the  inoculation  or  examina- 
tion made  as  soon  as  the  means  are  at  hand.  In  large  cities 
diphtheria  examinations  are  made  in  the  municipal  laboratory. 
The  inoculated  boxes  and  a  special  blank  properly  filled 
out  are  sent  in  by  the  physician,  and  a  report  can  be  had  the 
next  day. 

Pseudodiphtheria  Bacillus. 

This  organism  resembles  Bacillus  diphtherice  so  closely  in 
every  respect  that  the  question  has  been  raised  as  to  whether 
this  organism  is  not  the  diphtheria  bacillus  in  an  attenuated 
form  (Figs.  101  and  102).     It  has  been  found  in  the  diph- 


248 


BACILLUS  niPHTHEBIJS, 

Fig.  101. 


Small  type  of  pseudodiphtheria  bacilli.    X  1000.    (Park.) 
Fig.  102. 


Colonies  :  Diphtheria  bacilli :  a,  pseudobacillus ;  b,  true  bacillus ;  c,  pseudo- 
bacillus.    (Dunham.) 


PSEUDODIPHTHERTA  BACILLUS.  249 

theritic  membrane,  in  healthy  throats,  in  the  nose,  on  the  skin, 
and  on  the  conjunctivae,  especially  in  xerosis  conjunctivae. 
It  has  also  been  found  in  hnp^etigo,  acne,  pustules  of  variola, 
in  gangrene  of  the  lung,  and  ^h  pneumonia.  The  pseudo- 
diphtheria  bacillus  does  not  elaborate  a  toxin.  It  is  not 
virulent. 


CHAPTER    IX. 

SPIRILLUM   CHOLERA  ASIATICS. 

This  organism,  also  known  as  the  cholera  •yibrio  or  the 
comma  bacillus  of  Koch,  was  discovered  in  1883  in  the  dejecta 
and  intestines  of  cliolera  patients.  It  is  the  accepted  specific 
cause  of  Asiatic  cholera.     It  is  never  found  in  the  healthy 


Fig.  103. 


Spirillum  of  Asiatic  cholera,  from  a  bouillon  culture  three  weeks  old,  showing 
numbers  of  long  spirals.    X  1000.    (Fraenkel  and  Pfeiffer.) 


human   body  nor  in  any  other  part  of  the  cholera   patient 
except  the  intestines  and  their  contents. 

Morphology  and  biology :  The  cholera  bacillus  is  a  very  small, 
slightly  bent  rod,  wnth  rounded  ends,  and  resembles  a  comma, 
whence  its  name  (Fig.  103).     When  two  of  these  organisms 

260 


MORPHOLOGY  AND    BIOLOGY. 


251 


are  joined  end  to  end  they  resemble  the  letter  S  (Fig.  103). 
Long  chains  are  occasionally  formed  in  culture  (Fig.  106). 

The  cholera  bacillus  can  be  stained  with  the  anilin  dyes, 
but  with  some  difficulty.  It  stains  best  in  a  hot  carbol- 
fuchsin  solution.  It  does  not  stamlby  Gram's  methodr  It 
is  exceedingly  motile  and  has  terminal  flagella.     It  is  one  of 

Fig.  104. 


Spirillum  of  Asiatic  cholera :  colonies  two  days  old  upon  a  gelatin  plate.    X  35. 

(Heim.) 

the  mqnotjichia^ which  have  only  one  or  two  flagella  project- 
ing from  one  end.  It  does  not  form  spores,  althougli  Hueppe 
believed  that  arthrospore-formation  existed. 

It  is  strongly  aerobic^  growing  quite  readily  on  all  culture- 
media  either  atTHeroom  or  the  body  temperature,  but  the 
medium  must  be  slightly  alkalirifi,  as  the  cholera  spirillum  is 
quite  sensitive  to~iev'en  small  amounts  of  acid. 

Schottelius  gives  the  following  method  for  making  pure 
cultures  of  the  cholera  germ  :  A  small  quantity  of  the  intes- 
tinal mucus  or  fecal  matter  is  transferred  to  a  flask  or  tube 


252  SPIRILLUM  CHOLERA  ASIATICM 

Fig,  105. 


Spirillum  cholerse  Asiaticx :  gelatin  puncture-cultures  aged  forty-eight  and  sixty 
hours.    (Shakespeare.) 

containing  bouillon  which  is  slightly  alkaline,  and  placed  in 
the  incubator   for  twenty-four    hours.     The  growth   forms 

Fig.  106. 


Spirillum  cholerse  A siaticae :  involution-forms.    X  700.    (Van  Ermengen.) 

rapidly  in  the  shape  of  a  luxuriant  surface  membrane.     From 
this  membrane  plate  cultures  are  made. 


MORPHOLOGY  AND  BIOLOGY.  253 

In  gelatin  plates  colonies  appear  within  twenty-four  hours 
(Figs.  104  and  107).  They  are  very  small,  granular,  with  irreg- 
ular borders,  of  a  whitish  color,  and  develop  in  the  medium. 

Fig.  107.  Fig.  108. 


Cholera  colonies  in  gelatin :  twenty-four         Cholera  colonies  in  gelatin :  thirty- 
hours'  growth.    (Dunham.)  six  to  forty-eight  hours'  growth.     X 

about  80.    (Park.) 

These  colonies  gradually  turn  from  white  to  yellow  and  from 
yellow  to  brown^  at  the  same  time  liquefying  the  gelatin  quite 
rapidly  until  each  colony  occupies  a  small  con icaj jrlepressi on . 
The  old  colonies  are  very  granular  and  glistening  (Pig.  J 08). 


Cholera  colony  in  gelatin.    X  30.    (Dunham.) 


Their  appearance  at  this  time  is  that  of  a  dirty  granular  mass 
strewn  with  small  bits  of  glass.  Each  colony  is  surrounded 
by  a  transparent  halo  (Fig.  109).     The  colony  gradually  sinks 


254  SPIRILLUM  CHOLERM  ASIATICS, 

deeper  into  the  medium  as  liquefaction  progresses,  and  at  last 
turns  a  very  peculiar  pink. 

The  gelatin  stab  culture  is  also  quite  characteristic.  The 
growth  first  takes  place  along  the  entire  needle-track,  being 
more  profuse  on  and  near  the  surface,  where  the  supply  of 
oxygen  is  greater.  The  liquefaction  of  the  gelatin  keeps  pace 
with  the  growth,  beginning  at  the  top  as  a  small  funnel-shaped 

Fig.  110. 


A  characteristic  series  ot  cholera  cultures  m  gelatin:  one,  two,  three,  four,  and 
six  days'  growth.     (Dunham.) 

depression.  This  funnel  or  inverted  cone  gradually  increases 
in  size  until  all  the  gelatin  is  liquefied.  The  culture  slowly 
settles  to  the  bottom  of  the  funnel,  the  end  of  which  usually 
shows  a  slight  bulbous  enlargement  (Figs.  105,  110,  and 
111).  The  liquefied  gelatin  evaporates  slowly,  so  that  the  fun- 
nel is  empty  at  the  top.  It  looks  as  though  it  contained  an 
enormous  aiV  bubble.  At  the  end  of  four  or  five  weeks  lique- 
faction of  the  gelatin  is  complete.      According  to  different 


VITALITY.  .  255 

authorities,  the  organism  remains  alive  in  the  gelatin  tube 
for  from  eight  weeks  to  two  years. 

On  agar-agar  stroke  cultures  a  shining,  moist,  grayish- 
white  growth  develops  along  the  line  of  inoculation  (Fig. 
112).  The  growth  on  blood-serum  is  exactly  like  that  on 
agar,  but  the  blood-serum  is  liquefied. 

^guillony  even  when  very  dilute,  is  soon  clouded,  with  the 
formation  of  a  surface  membrane.  The  culture  m.^milk  is 
destroyed  by  the  formation  of  lactic,. acid.  On  jotot^  a 
grayish-brown,  translucent,  very  delicate  membrane  is  formed, 
even  when  the  potato  is  acid. 

If  it  is  desired  to  preserve  the  cholera  spirillum  for  a  long 
time,  it  should  be  transplanted  into  sterilized  water,  in  which 
it  develops  quite  rapidly  and  persistently.  It  also  retains  its 
vitality  for  a  long  time  if  wrapped  in  moist  linen. 

The  cholera  germ  also  produces  nitrites  and  indol.  The 
addition  of  a  few  drops  of  sulphuric  or  hydrochloric  acid  to 
cholera  cultures  containing  peptone  gives  a  beautiful  red  color, 
the  so-called  cholera-red  reaction,  which  is  characteristic  of 
this  organism.  The  cholera  bacillus  is  one  of  a  very  few 
germs  which  give  the  nitroso-indol  reaction.  This  is  used  as 
a  means  of  differentiation. 

Vitality :  The  cholera  spirillum  possesses  little  resisting 
power.  A  four  minute  exposure  to  a  temperature  of  52°  C. 
is  fatal.  Drying  also  destroys  it  very  quickly — within  a  few 
hours.  The  addition  of  a  very  small  quantity  of  acid  to  the 
culture-medium  immediately  inhibits  the  growth  of  the  organ- 
ism. Pettenkofer  claimed  that  when  the  cholera  organism 
is  brought  in  contact  with  normal  gastric  juice  it  is  destroyed 
immediately.  He  demonstrated  the  truth  of  this  by  swallow- 
ing a  pure  culture  of  cholera.  In  the  presence  of  a  little 
moisture  the  germ  retains  its  vitality  for  a  long  time.  When 
associated  in  culture  with  saprophytic  germs  its  development 
ceases.  Freezing  destroys  the  germ  in  a  few  days.  A  10 
per  cent,  solution  of  mercuric  chloride  or  a  3  per  cent,  solu- 
tion of  carbolic  acid  is  effective  immediately.  Milk  of  lime 
and  sulphate  of  copper  are  excellent  disinfectants  for  choleraic 
discharges.  High  temperatures  always  favor  the  development 
of  the  germ. 


256  SPIRILLUM  CROLERJE  ASIATICS. 

Pathogenesis :  Cholera  is  pathogenic  ft)r  man  only._  The 
disease  is  endemic  in  India,  and  all  epidemics  of  cholera  have 
had  their  origin  in  that  country.  The  habits  of  the  Hindoos 
and  their  religious  customs  are  largely  responsible  for  the 
constant  presence  of  this  disease.  Infection  follows  inges- 
tion of  the  germ  in  either  water  or  food.  The  disease  is 
probably  never  conveyed  through  the  air,  because  the  bacillus 
succumbs  so  rapidly  to  desiccation.  Furthermore,  the  germ 
must  find  its  way  to  the  intestinal  tract  before  the  disease  will 
develop.  It  is  possible  that  small  numbers  of  the  germ 
may  be  swallowed  with  impunity ;  but  it  is  more  probable, 
in  view  of  its  feeble  resistance  to  the  mineral  acids,  that 
there  must  be  some  abnormal  condition  of  the  stomach  which 
is  accompanied  by  a  diminution  in  the  secretion  of  hydro- 
chloric acid  or  its  total  suppression,  before  infection  can  take 
place. 

The  cholera  germ  multiplies  rapidly  in  the  intestinal  tract, 
with  elaboration  of  its  toxin,  which  is  absorbed  and  gives 
rise  to  the  symptoms  of  the  disease.  All  the  pathologic  lesions 
of  cholera  are  due  to  this  absorption  of  the  toxin. 

Infection :  The  stools  of  the  cholera  patient  are  the  infecting 
medium,  and  soiled  clothing  or  bed-linen  is  the  usual  means 
of  conveying  the  disease  to  others.  Emptying  the  dejecta 
into  a  sewer  or  depositing  them  on  the  ground  without  disin- 
fecting them,  causes  contamination  of  the  water-supply  if  the 
sewerage  is  imperfect  or  when  the  water  is  obtained  from 
wells  or  from  small  streams  or  creeks. 

Insects  which  feed  on  the  dejecta  may  carry  the  germs  and 
deposit  them  on  food  or  in  water  many  miles  distant  from  the 
original  source  of  the  disease. 

Pollution  of  the  water-supply  is  by  far  the  most  common 
and  also  the  most  dangerous  source  of  infection.  The  famous 
epidemic  of  cholera  in  London  had  its  origin  in  the  pollution 
by  cholera  dejecta  of  the  water-supply  derived  from  the  Broad 
Street  pump.  Nearly  every  individual  using  this  water  be- 
came infected  with  the  disease. 

In  India  the  natives  bathe  in  the  river  Ganges  as  a  religious 
practice,  and  the  dead  are  also  buried  in  the  river  no  matter 
what  the  cause  of  death  may  have  been.     At  those  times  of 


IMMUNITY.  257 

the  year  when  the  Hindoos  flock  to  the  Ganges  to  worship 
they  live  in  crowded  camps,  and  under  these  circumstances 
cases  of  cholera  are  always  very  numerous. 

Pettenkofer  believes  that  the  disease  is  never  transmitted 
from  one  individual  to  another,  but  that  the  germ  must  first 
mature  in  the  earth  for  a  certain  length  of  time  before  infec- 
tion can  occur.  He  also  believes  that  infection  occurs  through 
the  respiratory  tract.  His  theory  is  known  as  the  grounds 
ymterthegry^. 

Garden  vegetables  sprinkled  with  water  containing  the 
cholera  germ  ;  and  milk  which  is  either  diluted  with  or  con- 
tained in  cans  that  have  been  washed  in  infected  water,  may 

Fig.  111. 


stab  cultures  of  three  cholera  spirilla  in  gelatin,  showing  in  upper  portion  of 
growth  considerable  liquefaction  of  nutrient  gelatin.    (Park.) 

be  the  source  of  infection.  A  number  of  investigators  have 
become  infected  with  pure  cultures  of  cholera  while  conduct- 
ing experiments  in  the  laboratory  on  animals. 

Immunity :  The  serum  of  the  blood  of  animals  that  have 
recovered  from  cholera  contains  a  substance  which  has  decided 
bactericidal  properties.  This  substance  is  not  an  antitoxin. 
The  immunity  is  entirely  dependent  upon  lysogenjcity,  or  the 
formation  of  lysogenic_boclies  in  the  blood  which  possess  a 

17— Bact. 


258  SPIRILLUM  CHOLERA  ASIATICS. 

baqtericidal  action.  This  substance  is  not  found  in  the  blood 
until  after  the  first  week  of  convalescencCj  and  disappears 
within  four  weeks.  There  is  no  natural  immunity  to  cholera. 
Koch  believes  that  one  attack  conveys  a  permanent  immunity. 
The  blood-serum  of  immunized  animals  confers  immunity. 

Immunity  in  man  is  produced  by  a  form  of  vaccination 
which  was  first  proposed  by  Haffkine.  He  begins  by  inject- 
ing a  dead  culture,  and  five  days  afterward  he  follows  it  with 
an  injection  of  a  virulent  culture,  which  is  repeated  on  the 
tenth  day.  The  immunity  obtained  in  this  way  is  not  perma- 
nent, but  serves  merely  as  a  prophylactic  measure  or  a 
protective  during  epidemics  of  cholera.  The  production  of 
immunity  to  cholera  by  means  of  an  antitoxin  which  causes 

Fig.  112. 


Contact  smear  of  colony  of  cholera  spirilla  from  agar.  X  700,  (Dunham.) 

the  formation  of  lysogenic  bodies  in  the  blood  is  as  yet  a 
matter  of  dispute,  although  Haffkine's  results  have  been  very 
good.  It  is  at  best  only  a  protective,  the  efficacy  of  which 
cannot  be  depended  upon  at  all  times. 

Diagnosis :  A  flake  of  intestinal  mucus  is  spread  on  a  slide 
and  stained  with  a  hot  carbol-fuchsin  solution.  A  positive 
diagnosis  can  be  made  in  about  50  per  cent,  of  all  cases.  On 
the  whole,  it  is  preferable  to  cultivate  the  organism,  as  the 
results  obtained  in  this  manner  are  positive  in  each  case. 
Pure  cultures  are  made  as  already  described.  The  distinc- 
tive appearance  of  the  plate  culture,  the  gelatin  stab  culture, 
and  the  cholera-red  reaction  are  sufficiently  characteristic  to 
be  of  diagnostic  value.     Animal   experimentation  may  also 


CHOLERA  NOSTRAS  AND   CHOLERA   MORBUS,       259 

be  resorted  to  in  making  a  diagnosis.  A  small  quantity 
of  the  intestinal  discharge  is  injected  into  the  abdominal 
cavity  of  a  guinea-pig,  and  in  the  presence  of  the  cholera 
germ  a  choleraic  peritonitis  develops. 

Cholera  Nostras  and  Cholera  Morbus. 

A  large  and  varied  number  of  bacteria  have  been  found  in 
the  intestinal  discharges  of  patients  affected  with  cholera 
nostras  and  cholera  morbus,  e.  g,,  members  of  the  so-called 
colon  group,  especially  Bacterium  coli  communis.  Strepto- 
cocci have  also  been  found  and  a  large  variety  of  vibrios,  but 
not  the  cholera  vibrio.  The  acute  enteritis  of  children,  com- 
monly  known  as  summer  complaint,  is  believed  to  be  due  to 
Bacterium  lactis  (of  Fluegge)  or  a  peptonizing  milk  bacterium. 

At  the  present  writing,  reports  are  current  of  the  dis- 
covery of  a  specific  germ  in  summer  complaint,  but  no 
authentic  statement  has  as  yet  been  published  in  this  matter, 
and  it  is,  therefore,  impossible  to  give  even  a  brief  description 
of  this  organism.  The  meagre  information  at  hand  indicates 
that  the  germ  is  in  all  probability  Bacillus  dysenterice  or 
some  member  of  the  colon  group. 


CHAPTER  X. 

ORGANISMS    RESEMBLING    THE    CHOLERA   SPIRILLUM. 
Spirillum  of  Finkler-Prior  (Vibrio  Proteus). 

This  germ  was  found  in  the  intestinal  discharges  of 
patients  sick  with  cholera  nostras. 

Biology  and  morphology:  The  Finkler-Prior  spirillum  re- 
sembles the  cholera  organism  very  closely  in  contour,  but  is 
much  shorter  and  thicJieri.  and  it  does  not  form  such  long 
qhainsancT  spirals.  Its  ends  are  pointed  and  it  bulges 
slightly  in    the   centre.       Extending   from   one  end  of  the 

Ficx.  113. 


Spirillum  of  Finkler  and  Prior.     X  1100.     (Park.) 

organism  is  a  single  flagellum  (Fig.  113).  The  spirillum 
is  exceedingly  motile.  It  does  not  form  spores.  The  ordi- 
u^iy^MV^n^dyes^re  used  in  staining. 

It  is  a  facultative  anaerobe,  growing  readily  on  all  culture- 

260 


SPIRILLUM  UF   FINKLER-PRIOR. 


261 


media.  Its  growth  in  gelatin  is  characterized  by  an  ex- 
tremely rapid  and  characteristic  liquefaction  of  the  medium. 
On  gelatin  plates  small  white  colonies  form  in  the  medium. 
These  colonies  are  finely  granular,  with  very  sharply  marked 
borders  and  of  a  yellowish-brown  color,  which  is  more 
intense  in  the  centre  than  at  the  periphery  of  the  colony. 
They  are  surrounded  within  a  few  days  by  a  zone  of  lique- 
faction. These  colonies  can  be  differeiitiated  from  those  of 
the  cholera  spirillum  by  a  more  sharply  defined  border  and 

Fig.  114. 


Spirillum  of  Finkler  and  Prior :  colony  twentv-four  hours  old,  as  seen  upon  a 
gelatin  plate.    X  100.     (Fraenkel  and  Pfeiffer.) 

a  darker  color,  and  they  are  also  less  granular  (Fjg.  114). 
After  a  time  they  resemble  each  other  so  closefy  that  diiFer- 
entiation  is  impossible. 

In  the  gelatin  stab  liquefaction  progresses  very  rapidly  and 
forms  a  typical  stocking-shape^  which  is  filled  with  a  cloudy 
liquid.  The  surface  of  the  medium  is  usually  covered  with 
a  thick  whitish  membranous  growth.  Liquefaction  occurs 
much  more  rapidly  than  in  cholera  cultures.  The  stocking- 
shaped  liquefaction    is  peculiar  to  this  organism,  and  while 


262    ORGANISMS  RESEMBLING  THE  CHOLERA  SPIRILLUM. 

the  liquefied  j^latin  is  clouded  in  this  culture,  in  tlie  cholera 
culture  it  is  perfectly  clear,  the  culture  having  settled  to  the 
bottom  of  the  liquefaction  (Fig.  116). 

The  growth  on  qgmi  is  very  Juxurjant.  It  forms  a  heavy 
slimy  whitish  membrane  which  soon  covers  the  entire  surface 
of  the  medium.     On  potato  an  extensive  moist  grayish-yellow 

Fig.  115. 


« 


stab  culture  of  the  Finkler-Prior  bacillus  In  gelatin,  at  18°  to  20°  C. :  a,  after 
twenty-four  hours ;  6,  after  forty-eight  hours ;  c,  after  seventy-two  hours ;  d,  after 
ninety-six  hours.    (Abbott.) 


coating  is  formed.  The  growth  on^potato  develops  at  the 
room  temperature,  whereas  the  cjiolera  spirillum  will  not 
develop  on  potato  at  a  temperature  lower  than  that  of  the 
body.  Even  then  the  growth  is  very  slight  and  of  a  brownish 
color. 

Blood-serum  is  liquefied  rapidly.     The  growth  in  milk  is 


SPIRILLUM  DEN  EKE.  263 

very  slight.  No  growth  occurs  in  either  tap-water  or  steril- 
ized water.  There  is  no  cholera-red  reaction.  When  grown 
in  a  medium  containing  glucose,  acid^  is  produced.  The 
organism  resists  desiccation  much  better  than  the  cholera 
spirillum. 

Pathogenesis  :  Although  the  organism  is  pathogenic  for  some 
animals,  it  does  not  appear  to  be  the  cause  of  disease  in  man. 
It  is  most  frequently  found  in  the  intestinal  discharges  of  per- 
sons suffering  from  ^iarrhoea  or  cholera  nostras.  It  may  occa- 
sionally appear  in  the  feces  of  healthy  patients. 

Spirillum  Deneke  (Vibrio  Tyrogenum). 

Deneke  obtained  this  organism  from  old  cheese. 

Biology  and  morphology :  The  Sj)irillurri~l)eneke  resembles 
the  cholera  spirillum  even  more  than  does  the  Finkler-Prior 
spirillum.  It  is  a  very  short  curved  rod,  a  number  of  which 
may  form  tightly  coiled  chains  and  spirals  (Fig.  116).     It  is 

Fig.  116. 


*•->.     '^ 


Spirillum  tyrogenum.    X  700.    (Fluegge.) 


flagellated  and  actively  motile;  stains  like  the  cholera  bacillus; 
grows  equally  well  at  the  room  and  body  temperature ;  and 
does  not  form  spores.     It  is  a  facultative  anaerobe. 

The  colonies  on  the  gelatin  plate  differ  from  those  of 
cholera  in  that  they  develop  more  rapidly,  are  of  a  yellowish- 
greeii,color,  and  are  irregular  in  contour^with  sharply  defined 
borders  (Fig.  117).  The  medium  is  also  liquefied  more 
rapidly. 

In  the  gelatin  stab  the  stocking-shaped  liquefaction  is 
formed,  which  is  filled  with  the  cloudy  liquid,  the  culture  col- 


264    OEGANISMS  RESEMBLING  THE  CHOLERA  SPIRILLUM. 

Fig.  117. 


Spirillum  tyrogenum,  colonies  on  gelatin  plate :  a,  end  of  sixteen  hours ;  6,  end  of 
twenty-four  hours ;  c,  end  of  thirty -six  hours.    X  80.    (Fluegge.) 

lecting  in  the  bottom  in  the  form  of  a  coiled  mass.     The  gel- 
atin is  liquefied  completely  in  about  two  weeks  (Fig.  118). 

Fig.  118. 


i 


stab  culture  of  Deneke's  cheese  spirillum  in  gelatin,  at  18°  to  20°  C. :  a,  after 
twenty-four  hours ;  b,  after  fortj'-eight  hours  ;  c,  after  seventy-two  hours ;  d,  after 
ninety-six  hours,    (Abbott.) 

A  very  sparse  yellowish  membrane  is  formed  on  agar. 

Blood-serum  is  rapidly  liquefied. 

A  very  luxuriant  moist  yellow  film,  containing  many  long 


SPIRILLUM  METSCHNIKOVL  265 

spirals,  is  formed  on  j>oto^o_\yhen  grown  at  the  body  tempera- 
ture.    No  indol  is  produced. 

The  Spiiillum  Deneke  is  of  absolutely  no  importance  clin- 
ically except  for  its  resemblance  to  the  cholera  germ.  It  has 
never  been  found  in  the  secretions  or  excretions  of  either 
man  or  animals. 

Spirillum  Metschnikovi  (Spirillum  of  Gamaleia). 

This  organism  was  discovered  in  the  excretions  and  intes- 
tinal canal  of  chickens  affected  with  a  diarrhoeaic  disease  epi- 
demic in  southern  Russia  during  the  summer  months. 

Biology  and  morphology :  The  Spirillum  Metschnikovi  is 
shorter,  thicker,  and  more  curved  than  the  cholera  spirillum. 
It  forms  long  chains  and  spirals,  is  motile,  and  possesses  a 

Fig.  119. 


Spirillum  Metschnikovi,  from  an  agar-agar  culture.    X  1000.    (Itzerott  and 

MitimnriTi  \ 


Niemann.) 

terminal  flagellum.  It  does  not  form  spores.  It  is  only 
feebly  resistant  to  heat  and  chemicals.  It  grows  at  both  the 
body  and  the  room  temperatures :  stains  with  all  the  anilin 
dyes,  but  not  with  Gram.     It  is  a  facultative  anaerobe. 

Gelatin  plate  colonies  appear  in  about  twelve  hours  as  small 


266    OUGANISMS  RESEMBLING  THE  CHOLERA  SPIRILLUM. 

whitish  dots  (Fig.  120),  which   rapidly  increase  in    size   to 
form  yellowish-brown  masses.     When  liquefaction  occurs,  the 

Fig.  120. 


Colony  of  Vibrio  Metschnikovi  in  gelatin,  after  thirty  hours  at  20°  to  22°  C. 
X  about  75.    (Abbott.) 

colony  occupies  a  shallow,  saucer-shaped  depression.    The  edges 
of  the  colony  are  irregular  and  fringed  with  radiating  filaments. 

Fig.  121. 


stab  culture  of  Vibrio  Metschnikovi  in  gelatin,  at  18°  to  20°  C. :  a,  after  twenty-four 
hours;  b,  after  forty-eight  hours;  c,  after  seventy-two  hours;  d,  after  ninety-six 
hours.    (Abbott.) 

In  tube  cultures  on  agar,  gelatin,  and  blood-serum  the 
growth  closely  resembles  that  of  cholera,  but  it  develops  more 


OTHER   ORGANISMS  RESEMBLING  CHOLERA  GERM.  267 

rapidly  (Figs.  119  and  121).  On  potato,  at  the  incubator 
temperature,  a  heavj^  yellowish-brown' "or  chocolate-colored 
growth  develops. 

Bouillon  becomes  clouded  and  opaque,  a  thin  wrinkled 
membrane  forming  on  the  surface.  The  spirillum  is  not  gas- 
producing,  but  forms  acid  very  rapidly.  Milh  is  coagulated. 
'^h^chokm-red  reaction  is  very  apparent. 

The  organism  is  highly  pathogenic  for  animals,  especially 
chickens,  but  not  for  man. 

Other  Organisms  which  Resemble  the  Cholera  Germ. 

Spirillum  Berolinensis  was  discovered  by  Neisser  in  river- 
water.  It  very  closely  resembles  the  spirilla  already  described. 
It  is  not  pathogenic  for  man. 

Spirillum  Dunbar  is  also  a  water  vibrio.  It  differs  from  the 
cholera  organism  in  its  staining  reaction.  It  stains  very 
poorly  and  exhibits  polar  bodies.  Cultures  grown  at  low 
temperatures  are  said  to  be  phosphorescent. 

Spirillum  Danubicus,  found  in  water ;  Spirillum  Wernicke 
and  Spirillum  Bonhoffi;  Spirillum  Weibeli;  Spirillum  Milleri; 
Spirillum  Aquatilis;  Spirillum  terrigenus,  and  Vibrio  Schuyl- 
kiliensis,  are  all  non-pathogenic  for  man,  and  are  met  only 
occasionally.  Many  of  them  have  not  been  described  since 
they  were  discovered.  Most  of  them  are  found  in  water,  a 
few  in  the  soil. 

The  absolutely  characteristic  growth  of  the  cholera  organism 
will  in  each  instance  serve  to  differentiate  it  from  these  less 
common  forms. 


/?^^>>^' 


CHAPTEK  XI 


BACILLUS  TYPHOSUS. 

(Bacillus  Typhi  Abdominalis ;  Bacillus  of  Eberth;  Ebertli- 
Gaffky  Bacillus.) 

The  bacillus  of  typhoid  fever  was  discovered  by  both  Eberth 
and  Koch,  in  1880,  in  the  spleen  and  mesenteric  lympH^ 
glands"of  typhoid  cadavers,  and  was  first  isolated  and  studied 
in  pure  cultures  by  Gaifky  four  years  later. 

Biology  and  moTiploiology'r Bacillus  typhosus  is  a  small  thick 
rod,  with  pointed  ends  and  from  ten  to  eighteen  terminal  and 
lateral  flagella.     It  is  exceedingly  motile.     It  measures  from 


Fig.  122. 


Fig.  123. 


Typhoid  bacilli  from  nutrient  agar. 
X  1100.    (Park.) 


Typhoid  bacilli  from  nutrient  gelatin. 
X  1100.    (Park.) 


1  //  to  3/i  in  length,  and  from  0.5 //  to  0.8  jm  in  width.  There 
is  no  evidence  of  sporulatioji.  The  organism  is  extremely 
variable  in  cultures.  In  specimens  made  directly  from  the 
tissues  or  typhoid  excreta  the  germ  usually  occurs  singly 
but  in  culture  specimens  it  is  frequently  seen  to  form^hains, 
both  long  and  short  (Figs.  122,  123). 


BIOLOGY  AND  MORPHOLOGY. 


269 


The  bacillus  can  be  stained  ^^\ih  all  the  anilin  dyes,  but 
must  be  exposed  to  the  action  of  the  stain  for  a  long  time. 
To  facilitate  staining,  it  is  advisable  to  use  slightly  warmed 
staining  solutions.  It  is  decolorized  easily,  and  for  that  reason 
should  not  be  washed  in  anything  but  water.  Heavily  stain- 
ing granules  have  been  seen  in  the  body  of  the  organism,  and 
also  polar  granules.  These  were  at  one  time  believed  to  be 
spores,  but  because  of  their  feeble  resistance  to  heat  and 
chemicals  this   view   is   untenable.      They   are   undoubtedly 


Fig.  124. 


Bacillus  typhi  ahdominalis,  from  an  agar-agar  culture  six  hours  old,  showing  the 
flagella  stained  by  Loeffler's  method.    X  1000.    (Fraenkel  and  Pfeiffer.) 


polar  granules  or  vacuoles  caused  by  the  drying  and  fixing 
of  the  specimen  preparatory  to  staining.  Gram's  stain  is  not 
applicable.  The  flagella  (Fig.  124)  are  easily  stained  by  the 
usual  methods.  The  typhoid  bacillus  is  used  to  demonstrate 
the  existence  of  flagella  on  bacteria. 

Bacillus  typhosus  is  both  saprophytic  and  parasitic.  It  is 
a  facultative  anaerobe,  but  has  very  strong  aerobic  tendencies. 
It  will  develop  equally  well  at  both  the  room  and  body  tem- 
perature, although  the  growth  is  most  luxuriant  at  the  latter. 


270  BACILLUS  TYPHOSUS. 

On  gelatin  plates  both  deep  and  superficial  colonies  develop. 
The  deep  colonies  possess  no  particular  distinguishing  feature. 
They  are  quite  small,  round,  and  finely  granular.  They 
are  light  brown  in  color.  The  superficial  colonies  are 
much  larger,  transparent,  with  irregular,  serrated  edges,  and 
bluish-white  in  color.  The  colonies  are  usually  described  as 
having  the  shape  of_a,graipe  1^^^  (^^'g  125).  The  centre  of 
the  colony  is  a  very  light  yellowish-brown ;  the  periphery  is 


A  superficial  and  a  deep  colony  of  typhoid  bacnn  in  gelatin.    X  50.    (Park.) 

colorless  and  presents  a  reticular  arrangement.     The  gelatin 
is  not  liquefied. 

In  Elsner^s  medium  the  colonies  of  the  colon  bacillus 
appear  within  twenty-four  hours,  whereas  those  of  the 
typhoid  bacillus  do  not  appear  until  after  forty-eight 
hours.  The  typhoid  colonies  are  very  small,  round,  and 
finely  granular.  Unfortunately  for  purposes  of  differentia- 
tion the  colonies  of  the  colon  bacillus  occasionally  come  out 
in  successive  crops,  so  that  they  may  be  mistaken  for  typhoid 
colonies.     Close  watching  will  aid  in  the  differentiation. 


VITALITY.  271 

In  gelatin  stab  cultures  the  principal  growth  occurs  on  the 
surface  of  the  mediuni.  Along  the  track  of  the  needle 
development  is  extremely  slight.  The  surface  growth  re- 
sembles the  superficial  colonies  on  the  plate.  .  The  gelatin  is 
not  liquefied. 

Stroke  cultures  on  agar-agar  and  blood-serum  are  not  char- 
acteristic. A  thin  transparent  grayish  coating  is  formed 
along  the  line  of  inoculation.  Bouillon  is  clouded,  with  the 
occasional  formation  of  a  delicate  surface  membrane. 

The  growth  on  potato  is  quite  characteristic.  It  is  usually 
referred  to  as  the  "invisible  growth.j^  Even  after  two  or 
tliree  days  there  is  no  apparent  growth  on  the  surface  of  the 
potato,  but  when  the  })latinum  needle  is  slowly  and  gently 
passed  over  the  surface  it  meets  with  resistance,  due  to  a 
heavy  moist  but  absolutely  colorless  film  which  has  formed. 
By  reflected  light  the  growth  is  made  visible.  Occasionally 
the  growth  is  of  an  ochre  color,  or  even  brown  with  a  green- 
ish tinge.  This  growth  resembles  that  of  the  colon  bacillus 
on  potato. 

The  typhoid  bacillus  flourishes  in  milk  without  changing 
the  medium  in  any  way.  At  times  it  may  produce  a  very 
slight  amount  of  acid,  although  as  a  rule  it  is  not  acid-produc- 
ing. Neither  does  it  cause  fermentation.  It  does  not  pro- 
duce aromatics.  These  characteristics  serve  to  identify  the 
typhoid  bacillus,  and  to  differentiate  it  from  the  colon  bacil- 
lus, which  resembles  it  in  every  other  respect. 

Vitality :  One  of  the  peculiarities  of  this  organism  is  its 
resisting  power.  It  will  remain  alive  in  distilled  water  for 
three  months.  In  ordinary  water  the  bacilli  disappear  within 
a  week  or  two  because  of  the  vigorous  growth  of  the  other 
bacteria  contained  in  the  water.  In  quiescent  pools  of  water 
the  typhoid  bacillus  will  remain  alive  for  a  month.  When 
contained  in  water  for  any  length  of  time,  its  appearance  is  so 
changed  that  recognition  is  impossible.  It  has  been  found  to 
retain  its  vitality  in  milk  for  five  weeks.  Transplanted  into 
the  upper  layers  of  the  soil,  it  remains  alive  for  nearly  six 
months.  AYhen  nutrient  bouillon  is  poured  over  the  soil  the 
germ  will  retain  its  vitality  for  twelve  months.     In  feces  it 


272  BACILLUS  TYPHOSUS. 

persists  for  three  or  four  months  if  not  too  many  other  sapro- 
phytic germs  are  contained  in  it. 

Repeated  freezing  and  tliavving  does  not  affect  the  vitality 
of  the  germ,  but  a  ten-minute  exposure  to  a  temperature  of 
60°  C.  is  invariably  fatal.  Neither  can  it  resist  desiccation. 
Carbolic  acid,  in  a  1  or  2  per  cent,  solution,  has  no  effect  on 
the  germ.  This  resistance  to  carbolic  acid  is  utilized  in 
obtaining  pure  cultures.  Dried  in  a  thin  layer,  the  typhoid 
bacilli  preserve  their  vitality  on  linen  for  from  sixty  to 
seventy  days,  on  wood  for  thirty-two  days,  and  on  buckskin 
for  eighty  days.  Hermetically  sealed  bouillon  cultures 
remain  alive  for  more  than  a  year. 

Isolation :  Pure  cultures  can  be  procured  from  the  feces  of 
typhoid  patients,  but  not  until  the  second  week,  and  even 
then  with  difficulty  unless  the  feces  contain  very  few  contami- 
nating germs.  Repeated  attempts  may  have  to  be  made 
before  the  organism  is  finally  isolated. 

It  is  preferable  to  make  the  culture  from  the  spleen  or  the 
mesenteric  lymph-glands  or  Peyer^s  patches  of  typhoid  fever 
cadavers,  but  the  autopsy  must  be  made  as  soon  as  possible. 

The  method  of  making  the  pure  culture  is  as  follows : 
Add  a  0.05  per  cent,  solution  of  carbolic  acid  to  each  of 
several  tubes  of  liquefied  gelatin.  A  small  piece  of  tissue  or 
several  loopfuls  of  feces  are  transplanted  to  tube  No.  1. 
Tube  No.  2  is  inoculated  from  tube  No.  1,  and  tube  No.  3 
from  tube  No  2.  The  contents  of  each  tube  are  then  plated 
or  rolled.  The  saprophytes  do  not  develop  because  of  the 
carbolic  acid  which  has  been  added  to  the  medium,  but  the 
growth  of  the  typhoid  bacillus  and  Bacillus  coli  communis  is 
not  interfered  with  in  the  least.  The  colonies  of  these  two 
varieties  must  be  differentiated. 

In  order  to  aid  in  this  differentiation,  Eisner  uses  a  special 
medium  for  plating.  It  is  prepared  as  follows  :  1  kilogram 
of  potato,  preferably  the  small,  red,  German  variety,  is  mace- 
rated in  1  liter  of  water  for  twelve  hours.  The  juice  is 
thoroughly  expressed  and  filtered  cold,  to  separate  as  much 
starch  as  possible.  The  filtrate  is  boiled  and  filtered  again. 
The  resulting  clear  fluid  is  neutralized  by  adding  2^  to  3  c.c. 
of  a  decinormal  solution  of  sodium  hydrate  to  each  10  c.c,  of 


ISOLATION. 
Fig.  126. 


273 


Hiss'  plate  media:  small  light  colony  (<)  is  composed  of  typhoid  bacilli;  large 
colony  (c)  of  colon  bacilli.    (Hiss.) 

juice.     Either  litmus-paper  or  phenolphthalein  may  be  used 
to  determine  the  reaction,  which   should   be  just  perceptibly 

Fig.  127. 


Colony  of  typhoid  bacilli  highly  magnified.    (Hiss.) 

acid.     The  solution  is  then  heated  and  10  per  cent,  of  nutri- 
ent gelatin  added,  after  which  the  medium  is  again  neutralized 

18— Bact. 


274  BACILLUS  TYPHOSUS. 

to  the  same  point  as  before,  filtered,  and  1  per  cent,  of  potas- 
sium iodide  added.  The  typhoid  and  coToiT~Bacillus  are  tlie 
only  organisms  tliat  will  grow  on  this  medium,  the  colonies 
of  the  colon  bacillus  appearing  some  time  before  those  of  the 
typhoid  bacillus  (Figs.  126  and  127). 

Another  method  for  isolating  the  typhoid  bacillus  from  the 
feces  is  proposed  by  Drigalski  and  Conradi:  Agar  containing 
2  per  cent,  of  peptone  and  1  per  cent,  of  nutrose  is  used.  To 
this  are  added  130  c.c.  of  litmus  solution,  containing  15 
grams  of  milk-sugar,  2  c.c.  of  a  10  per  cent,  soda  solution, 
and  10  c.c.  per  liter  of  ^'  Krystall  violett-Hoechst  ^^  solution. 
This  medium  is  plated  in  Petri  dishes.  After  it  has  hardened, 
the  material  is  spread  over  the  surface  of  the  plate  in  a  thin 
film.  After  this  film  has  dried  thoroughly  the  plates  are 
placed  in  the  incubator.  In  about  fifteen  hours  the  colonies 
are  distinctly  visible.  Those  of  the  colon  bacillus  are  from  2 
to  6  mm.  in  diameter  and  red  in  color.  The  typhoid  colonies 
are  about  half  that  size,  smooth,  dew-drop-like,  and  blue. 
The  colonies  are  examined  microscopically  and  the  results 
verified. 

Pathogenesis:  Typhoid  fever  is  unquestionably  due  to 
Bacillus  typhosus,  although  thus  far  it  has  been  impossible 
to  produce  typhoid  fever  experimentally  in  animals.  It  is 
never  found  in  the  tissues  of  a  healthy  individual,  and  it  is 
constant  in  the  lesions  of  typhoid  fever.  During  the  conva- 
lescent period  it  can  also  be  found  in  the  excreta,  especially 
the  urine.  When  an  animal  is  inoculated  with  a  pure  culture 
of  the  germ,  it  dies  with  symptoms  of  intoxication.  In  man, 
ingestion  of  the  bacillus  is  followed  by  the  typical  disease, 
providing  the  conditions  are  favorable  to  the  development  of 
the  organism.  To  all  appearances,  man  possesses  a  certain 
degree  of  immunity  to  typhoid,  and  a  special  predisposition, 
either  general  or  local,  such  as  convalescence  from  some  other 
disease,  or  an  acute  intestinal  catarrh,  is  necessary  before 
infection  can  take  place. 

Infection:  Although  infection  may  occur  by  way  of  the 
respiratory  tract  by  inhaling  dust  containing  the  typhoid 
germ,  yet  the  digestive  tract  is  the  usual  portal  of  entry  for  the 
germ.     The  natural  resistance  of  the  germ  to  acids  enables  it 


INFECTION.  275 

to  pass  through  the  stomach  and  to  reach  the  intestinal  tract, 
where  it  finds  a  lodgement  and  develops.  The  bacillus  usually 
gains  entrance  into  tlie  body  through  the  agency  of  food  or 
drink,  or  infection  may  occur  by  coming  in  contact  with  any 
article  which  has  become  contaminated  by  the  discharges  of  a 
person  sick  with  typhoid,  such  as  clothing,  bed-linen,  or  eat- 
ing utensils. 

Epidemics  of  typhoid  fever  are  usually  due  to  contamination 
of  drinking-water  or  milk  by  the  alvine  discharges  of  typhoid 
patients.  The  washing  of  milk-cans  with  water  contaminated 
with  the  excreta  of  typhoids  or  with  the  typhoid  bacillus  is 
a  common  mode  of  infection.  Several  epidemics  of  unusual 
severity  have  been  recorded  which  had  their  origin  in  the 
water  used  to  wash  milk-cans  or  to  dilute  milk.  In  such 
epidemics  the  cases  of  typhoid  are  usually  scattered  or  occur 
in  groups,  distributed  along  the  route  of  the  milkman. 
Garden  vegetables  which  have  been  sprinkled  with  infected 
water  may  also  convey  the  disease ;  they  should  never  be 
eaten  uncooked. 

Insufficient  disinfection  or  careless  disposition  of  the  feces 
and  urine  of  typhoids  is  the  source  of  contamination  of  the 
Avater-snpply.  If  the  excreta  of  every  case  of  typhoid  fever 
were  thoroughly  disinfected  before  they  are  disposed  of,  the 
disease  could  be  stamped  out.  Infection  of  the  water-supply 
may  occur  in  many  ways.  Occasionally  it  is  extremely  diffi- 
cult to  account  for  the  occurrence  of  epidemics  of  typhoid 
fever,  but  a  diligent  search  will  always  result  in  locating 
the  source  of  the  infection.  It  must  be  borne  in  mind  that 
when  the  excreta  are  thrown  on  the  ground  or  into  a  privy 
vault  they  invariably  filter  through  the  ground  and  in  that 
way  may  reach  the  water-supply.  Of  course,  modern  sani- 
tation and  efficient  drainage  have  done  much  to  eradicate 
this  evil,  but  in  rural  districts  these  do  not  obtain.  A  well 
or  rain-water  barrel  may  be  on  a  lower  level  than  the  privy 
vault  or  sewer,  or  not  far  aww  from  it,  and  the  water- 
supply  be  polluted  in  that  way.  Every  case  of  typhoid  fever 
has  its  origin  in  a  previous  case,  and  it  is  important  to  find 
the  source  of  contamination  to  prevent  an  epidemic  of  the 
disease. 


276  BACILLUS  TYPHOSUS. 

Unhygienic  surroundings  are  also  an  important  factor  in  the 
causation  of  typhoid  fever.  Damp,  dark,  and  dirty  houses, 
and  tenements  especially,  undermine  the  natural  resisting 
power  of  the  individual,  and  he  more  readily  falls  a  prey  to 
infections,  particularly  typhoid  fever,  which  is  a  filth  disease. 
Personal  cleanliness  means  health  and  the  power  to  ward  off 
infections. 

After  the  typhoid  bacillus  has  gained  entrance  to  the  intes- 
tinal canal  it  lodges  in  the  Peyer's  patches  and  the  solitary 
lymph-follicles  in  the  mucosa  of  the  bowel.  Here  it  multi- 
plies and  produces  the  local  symptoms  of  the  disease.  The 
infection  travels  through  the  lymphatics  to  the  mesenteric 
lymph-glands,  the  spleen,  liver,  and  kidneys.  The  bacillus 
may  also  make  its  way  into  the  blood-current  and  into  the 
bone-marrow  and  distant  parts  of  the  body.  The  bacilli  have 
also  been  found  in  the  rose  spots.  It  is  possible  to  make  pure 
cultures  of  Bacillus  typhosus  from  the  blood  and  from  the 
rose  spots. 

The  U7^ine  frequently  contains  the  bacilli,  especially  when 
the  kidneys  have  been  involved.  The  urine  may  be  the 
source  of  infection.  Even  after  convalescence,  for  as  long  as 
two  or  three  weeks,  the  urine  may  contain  the  bacillus.  It 
is  fully  as  important  to  disinfect  the  urine  thoroughly  as  it  is 
to  disinfect  the  feces. 

The  typhoid  bacilli  can  always  be  found  in  the  gall-bladder ; 
occasionally  in  the  lungs,  meninges,  heart,  and  testicles,  espe- 
cially when  these  organs  are  the  seat  of  typhoid  complications. 
The  bacillus  has  been  found  in  an  abscess  of  the  brain,  and 
in  other  suppurative  lesions  that  have  developed  in  the  course 
of  or  after  an  attack  of  typhoid  fever. 

The  lymphatic  hyperplasia  seen  so  frequently  in  the  internal 
organs,  especially  the  liver  and  spleen,  is  due  to  the  toxin 
elaborated  by  the  typhoid  bacillus.  It  was  at  one  time 
assumed  that  the  typhoid  bacillus  never  left  its  habitat  in  the 
intestinal  canal,  and  that  the  various  complications  were  due 
to  the  toxin.  This  opinion  is  not  held  now,  as  the  bacillus 
has  been  found  and  identified  in  the  complicating  lesions  of 
typhoid. 

Puncture  of  the  spleen  has  been  advocated  as  a  means  of 


BACTERIOLOGIC  DIAGNOSIS.  277 

diagnosis  in  typhoid  fever,  as  the  bacilli  make  their  way  into 
this  organ  very  early  in  the  disease.  The  dangers  connected 
with  such  a  procedure  are  manifest,  and  prohibit  the  encour- 
agement of  any  such  method  as  a  routine  practice  by  the 
average  practitioner. 

In  a  very  few  instances  the  bacillus  has  been  found  in  the 
sweat;  and  in  the  sputum  and  the  mucus  obtained  from  the 
throat.  In  typhoidal  pneumonia — that  is,  a  pneumonia  due 
to  the  typhoid  bacillus — this  organism  is  constant  in  the 
sputum. 

Mixed  and  secondary  infection :  Typhoid  fever  is  rarely  a 
pure  infection.  Bacillus  typhosus  is  most  frequently  asso- 
ciated with  Bacterium  coli  communis  and  the  streptococcus 
pyogenes.  The  colon  bacillus  is  held  responsible  for  most  of 
the  complications  of  typhoid  fever,  such  as  peritonitis,  chol- 
angitis, etc.  The  streptococcus  is  the  cause  of  otitis  media, 
bronchopneumonia,  and  empyema.  The  severe  prostration, 
resembling  sepsis,  occasionally  seen  in  aggravated  cases  of 
this  disease  is  invariably  due  to  a  mixed  or  secondary  infec- 
tion with  the  streptococcus.  Staphylococci  and  diplococci, 
especially  the  pneumococcus,  are  occasionally  associated  with 
the  typhoid  bacillus.  Nearly  all  the  pulmonary  complica- 
tions, however,  are  due  to  either  the  streptococcus  or  Bacillus 
typhosus.  The  pneumococcus  causes  the  secondary  pneu- 
monia, but  not  the  complicating  pneumonia. 

Bacteriologic  diagnosis :  The  close  resemblance  of  the 
typhoid  bacillus  to  the  colon  bacillus  makes  its  diagnosis  a 
matter  of  some  difficulty.  In  fact,  it  can  only  be  done  by 
cultivating  the  organism  and  noting  the  cultural  differences 
between  the  two.  The  bacillus  is  obtained  from  the  feces, 
urine,  blood,  etc.,  and  examined  microscopically.  The 
typhoid  bacillus  is  more  motile  and  has  more  flagella  than  the 
colon  bacillus,  but  such"  differences  afe~  not  very^  reliable. 
These  two  germs  also  stain  alike.     Their  cultures  are  alike 


except  on  potato,  on  which  the  ty^oid  forms  an  invisible^ 
growtli;  and  the  colon  bacillus  a  heavy~bipwnii ' 
with  slight  greenish  discoloration  ofTEe  potatoT 


Additional  points  of  differentiation  are  the  following 


278  BACILLUS  TYPHOSUS. 

/      (1)  The  colon  bacillus  coagulates  milk ;  the  typhoid  does 
'  not.  " ■ 

(2)  The  colon  bacillus  evolves  gas,  especially  in  media  con- 
taining grape-sugar ;  the  typhoid  does  not. 

(3)  The  colon  bacillus  gives  the  indol  reaction  when  grown 
in  Dunham's  solution  ;  the  typhoid  ^oes  not. 

(4)  The  colon  bacillus  is  distinctly  a^id-producing ;  the 
typhoid  usually  produces  no  acid  or  onlyaT^very^slight 
amount. 

Occasionally,  however,  varieties  of  either  organism  are  met 
with  that  do  not  answer  to  these  specific  reactions,  so  that  the 
differentiation  can  never  be  said  to  be  absolute.  The  Widal 
test  might  be  of  assistance,  but  even  here  variations  may 
occur.  Pfeiffer's  phenomenon  is  also  of  value  in  the  differ- 
entiation. 

When  the  bacillus  is  obtained  from  the  spleeUy  the  cultures 
are  made  from  the  fluid  obtained  from  this  organ.  The 
method  of  puncture  is  the  same  as  that  used  in  all  explora- 
tory punctures,  but  the  danger  from  sepsis  is  much  greater, 
because  the  typhoid  bacillus  is  capable  of  causing  suppura- 
tion. The  wound  in  the  spleen  may  be  the  starting-point  of 
a  fatal  septic  peritonitis. 

Widal  reaction :  A  most  valuable  aid  in  the  clinical  diag- 
nosis of  typhoid  fever  is  the  Widal  reaction  or  the  agglutina- 
tion-test. It  is  not  an  absolute  test,  but  when  carefully  and 
properly  performed  it  is  of  considerable  diagnostic  value. 
The  blood-serum  of  the  typhoid  patient  mixed  with  a  pure 
culture  of  the  typhoid  bacilli  yields  the  agglutination  phe- 
nomenon of  Gruber.  The  blood  is  obtained  through  an 
aseptic  puncture  of  the  tip  of  a  finger  or  the  lobe  of  the  ear, 
or  directly  from  a  vein.  If  the  blood  thus  obtained  is  not  to 
be  used  immediately,  it  is  allowed  to  coagulate  on  a  sterile 
piece  of  isinglass ;  or  in  an  emergency,  on  a  piece  of  paper  or 
on  blotting-paper.  The  blood-serum  retains  its  agglutinating 
power  for  months,  and  may,  therefore,  be  sent  any  distance 
for  diagnosis. 

The  test,  as  a  rule,  is  not  applicable  until  after  the  first 
week.  Fraenkel  observed  the  reaction  in  one  case  on  the 
second  day.     It  disappears  during  convalescence,  although  in 


BAGTERIOLOGIC  DIAGNOSIS. 


279 


exceptional  instances  it  has  persisted  for  years.  It  is  impor- 
tant to  ascertain  whether  or  not  the  patient  has  had  a  previous 
attack  of  typhoid  fever,  as  in  that  event  the  reaction  would 
not  hold  good  for  the  illness  which  may  be  present  at  that 
particular  time. 

The  Widal  test  is  performed  as  follows  (Widal,  when  he 
first  described  his  method,  advocated  the  use  of  fresh  blood- 
serum,  but  since  then  Wyatt  Johnson,  of  Montreal,  sug- 
gested the  use  of  dried  serum) :  The  blood  is  obtained  as 
already  described,  and  is  mixed  with  from  5  to  10  times  its 


Fig.  128. 


Widal  reaction :  bacilli  gathered  into  one  large  and  two  small  clumps,  the  few 
isolated  bacteria  being  motionless  or  almost  so.    (Park.) 

bulk  of  sterile  water.  If  the  blood-serum  is  dried,  it  is  first 
brought  into  solution  with  sterile  water.  To  a  drop  of  this 
mixture  placed  on  a  clean  cover-glass  is  added  a  platinum 
needle  loopful  of  an  eighteen  to  twenty-four-hour-old  bouillon 
culture  of  typhoid  bacillus,  and  the  two  are  thoroughly  mixed. 
The  drop  is  rimmed  with  vaselin  and  the  cover-glass  inverted 
over  a  concave  slide.  The  drop  is  examined  with  an  ordi- 
nary high  power  (^)  lens. 

The  first  change  noted  in  the  drop  is  that  the  bacilli  gradu- 


280  BACILLUS  TYPHOSUS, 

ally  lose  their  motility,  and  then  they  are  seen  to  gather  in 
small  bunches  or  clumps  (Fig.  128).  The  more  marked  this 
clumping  and  loss  of  motility,  and  the  earlier  the  reaction 
occurs,  the  more  positive  is  the  diagnosis.  Ordinarily  this 
reaction  begins  to  be  noticed  in  about  half  an  hour,  but  in 
some  instances  it  does  not  appear  before  an  hour  or  two. 
If  the  blood  contains  little  agglutinating  substance,  the  reac- 
tion does  not  occur  until  late  and  is  not  characteristic.  When 
blood  other  than  typhoid  is  mixed  with  the  typhoid  culture, 
the  bacilli  may  lose  their  motility,  but  the  loss  of  motility  is 
never  complete  nor  is  the  clumping  perfect.  Some  experience 
is  necessary  before  any  degree  of  efficiency  is  attained  in 
interpreting  this  phenomenon.  The  typhoid  culture  should  not 
be  more  than  twenty-four  hours  old,  and  should  be  virulent. 
Bouillon  cultures  should  always  be  used.  It  is  not  necessary 
to  sterilize  the  blood-serum  obtained  from  the  patient. 

Examination  of  water  for  typhoid  bacilli :  In  the  examina- 
tion of  water  for  the  Bacillus  typhosus,  its  resistance  to  car- 
bolic acid  is  a  valuable  aid  in  its  isolation.  From  0.05  to 
0.25  per  cent,  of  carbolic  acid  is  added  to  the  suspected  w^ater. 
Gelatin  plates  are  made  from  this  water  according  to  the 
method  of  Eisner.  As  the  specimen  of  water  may  contain 
only  a  few  bacteria,  it  is  necessary  that  many  examinations 
be  made.  The  examination  can  be  facilitated  by  adding  20° 
c.c.  of  a  standardized,  sterilized,  concentrated  solution  of 
peptone  and  sodium  chloride  to  100  c.c.  of  carbolized  water. 
The  mixture  is  placed  in  the  incubator,  and  in  about  twenty- 
four  hours  gelatin  plates  are  made  from  this  mixture.  Any 
growth  which  takes  place  is  either  the  typhoid  or  colon 
bacillus.  The  differentiation  is  made  as  described  above.  It 
is  advisable  to  make  several  tests  at  the  same  time,  as  that 
will  still  further  facilitate  the  work. 

Prophylaxis :  The  prophylaxis  in  typhoid  consists  of  the 
strictest  antiseptic  precautions.  All  the  intestinal  discharges 
and  urine  must  be  disinfected  at  once  and  thoroughly  as 
described  in  the  chapter  on  Disinfection.  The  same  is  true 
of  soiled  linen  or  clothing.  The  attendants  must  be  careful 
not  to  infect  themselves  by  coming  into  direct  contact  with 
infective  material.     Reinfection  of  the  patient  is  avoided  by 


PROPHYLAXIS.  281 

thorough  cleansing  of  the  nates  with  a  bichloride  solution 
after  each  evacuation  of  the  bowel. 

In  the  typhoid  circular  sent  out  by  the  Board  of  Health 
of  the  city  of  Chicago  the  following  directions  are  given  for 
avoiding  the  possibility  of  infection  with  Bacillus  typhosus: 

''  Boil  all  drinking-water  for  twenty-five  or  thirty  minutes. 

"  Pasteurize  all  milk  and  cream,  especially  for  the  young. 
If  you  do  not  know  how  to  pasteurize,  ask  your  druggist,  or 
the  nearest  dispensary,  or  your  family  doctor.  Five  minutes' 
instruction  will  teach  you,  and  it  costs  nothing  to  speak  of. 

'^  Dirty  hands  may  also  carry  the  typhoid  poison.  There- 
fore, wash  your  hands  carefully  before  handling  any  article 
of  food  or  drink. 

^^  Food  gets  poisoned,  especially  green  stuff,  by  being  ma- 
nured with  night-soil  ;  by  flies  crawling  over  it  after  feasting 
on  a  typhoid  discliarge,  of  which  they  are  especially  fond ; 
and  often  by  the  filthy  dust  of  the  street.     Therefore ; 

"  Wash  thoroughly  all  vegetables  and  fruit  intended  to  be 
eaten  raw.  Wash  in  water  that  has  been  boiled  and  then 
cooled.  Keep  flies  out  of  the  house  as  much  as  possible  by 
screens  and  fly-paper.  Cover  all  food-supplies  so  that  flies 
may  not  have  access  to  them." 

In  the  same  leaflets  are  contained  the  following  instructions 
for  disinfecting  typhoid  excreta : 

''  If  all  discharges  of  every  existing  case  of  typhoid  fever 
were  instantly  disinfected,  there  would  be  no  more  typhoid 
fever  in  the  world.     Therefore  : 

"  If  you  are  so  unfortunate  as  to  have  a  case  of  typhoid  in 
the  family,  disinfect  every  discharge  as  a  duty  to  your  neigh- 
bors as  well  as  to  prevent  others  of  the  family  from  getting 
poisoned. 

"  Sulphate  of  copper  (blue  vitriol)  is  the  best  typhoid  disin- 
fectant, one  pound  costing  ten  cents,  dissolved  in  two  and  a 
half  gallons  of  water.  Keep  a  pint  of  this  in  the  vessel  for 
the  discharges  from  both  the  bowel  and  the  bladder.  Stir 
thoroughly  for  a  few  minutes ;  let  stand  for  fifteen  minutes 
and  the  poison  will  be  destroyed.  Do  not  allow  any  discharge 
from  either  the  bowels  or  the  bladder  to  be  received  or  dis- 
posed of  except  in  this  manner." 


282  BACILLUS  TYPHOSUS. 

Furthermore,  the  people  are  cautioned  against  unhygienic 
surroundings,  damp,  dirt,  garbage,  and  neglect  of  personal 
cleanliness. 

Immunization :  It  is  possible  to  immunize  animals  to  typhoid. 
Rabbits  are  injected  with  gradually  increasing  doses  of  either 
living  or  dead  typhoid  bacilli  until  the  desired  degree  of 
immunity  has  been  attained.  The  blood-serum  of  such  rabbits 
is  bactericidal  and  also  slightly  antitoxic.  Several  investiga- 
tors have  observed  that  the  blood-serum  of  persons  convales- 
cent from  typhoid  fever  possesses  the  same  properties  as  the 
blood-serum  of  immunized  animals. 

It  is  a  matter  of  record  that  typhoid  fever  rarely  attacks 
the  same  individual  more  than  once,  so  that  the  inference  can 
be  made  that  one  attack  confers  immunity.  The  blood-serum 
of  typhoid  patients  possesses  immunizing  properties  when 
injected  into  animals  inoculated  with  typhoid  bacilli. 

Preventive  inoculation  with  sterilized  cultures  of  typhoid 
bacilli  appears  to  be  of  considerable  value.  All  the  reports 
made  show  that  by  far  the  greater  majority  of  persons  inocu- 
lated in  this  manner  did  not  acquire  the  disease.  The  inocu- 
lation is  followed  by  a  febrile  reaction,  which  lasts  for  about 
one  day,  and  which  produces  the  agglutinating  substance  in 
the  blood.  The  inoculation  should  be  repeated  in  about  two 
weeks.  A  dose  of  0.75  c.c.  of  the  serum  is  given  at  each 
inoculation. 

The  blood-serum  of  typhoid  convalescents,  as  well  as  steril- 
ized cultures,  have  been  used  for  curative  purposes  in  typhoid 
fever,  but  the  results  have  been  of  such  a  nature  that  it  is 
impossible  at  this  time  to  pass  any  opinion  on  the  serum 
treatment  of  typhoid  fever.  One  investigator  used  a  glycerin 
extract  of  the  thymus,  spleen,  bone-marrow,  brain,  and  spinal 
cord  of  animals  dead  of  typhoid,  and  reported  extremely 
gratifying  results  from  its  use  in  eighteen  cases.  Other  clini- 
cians report  a  decided  falling  off  in  the  mortality,  and  also  a 
much  shorter  duration  of  the  disease. 


CHAPTER    XII. 

ORGANISMS  RESEMBLING  THE  BACILLUS  TYPHOSUS. 
Bacillus  Coli  Communis     (Bacillus  of  Escherich). 

This  organism,  when  first  discovered  by  Emmerich  in 
1885,  was  believed  to  be  the  cause  of  Asiatic  cholera  yTut 
one  year  later  £scherich  demonstrated  that  it  was  found  in 
the  fecal  discharges  of  healthy  persons  and  animals  and  in 
the  water  and  soil  contaminated  with  their  discharges.  The 
exact  identity  of  this  bacillus  has  ever  since  been  the  subject 
of  much  discussion  and  controversy.  It  has  been  described 
as  a  non-virulent  variety  of  the  typhoid  bacillus  ;  and  as  a 
germ  closely  allied  to  the  typhoid  bacillus.  It  has  also  been 
stated  that  the  typhoid  bacillus  was  really  an  involution-form 
of  the  colon  bacillus. 

The  colon  bacillus  very  closely  resembles  the  typhoid 
bacillus  in  its  morphology  and  biology: 

It  is  a  short,  thick  rod,  with  rounded  ends,  measuring  from 
1  //  to  3  /i  in  length,  and  from  4  //  to  7  //  in  width  (Fig.  129). 
Oval  forms  and  thread  forms  are  also  met  with  in  culture. 
It  stains  like  Bacillus  typhosus,  and  occasionally  exhibits 
unstained  portions  resembling  spores,  but  it  does  not  sporu- 
late.  It  has  from  eight  to  ten  terminal  and  lateral  flagella 
and  is  actively  motile.  It  is  a  facultative  anaerobe,  and 
grows  readily  on  all  culture-media  at  either  the  room  or  body 
temperature. 

The  colonies  on  the  gelatin  plate  are  a  little  larger  than 
those  of  the  typhoid  bacillus  and  they  appear  earlier.  The 
superficial  colonies  are  small  and  leaf-shaped.  The  deep 
colonies  are  yellowish-brown  in  color,  round,  and  finely 
granular.     The  medium  is  not  liquefied. 

In  gelatin  stab  cultures   a   nail   growth  is  formed  without 


284   OBGANISMS  RESEMBLING  BACILLUS  TYPHOSUS 

liquefaction  of  the  gelatin.  On  agar-agar  and  blood-serum 
a  heavy,  grayish-white,  moist,  translucent  film  develops  along 
the  track  of  the  needle.  Bouillon  is  clouded,  but  as  the 
growth  settles  to  the  bottom  of  the  tube  the  bouillon  becomes 
clear.     A  surface  membrane  is  formed  at  times. 

In  media  containing  peptone  indol  is  formed.  Its  growth 
in  media  containing  sugar  is  accompanied  by  the  evolution  of 
much  gas,  sufficient  to  break  the  medium  into  chunks.  The 
fermentation-tube  can  be  used  to  demonstrate  gas-production. 

Fig.  129. 


Colon  bacilli :  twenty-four-hour  agar  culture.     X  1100.    (Park.) 

Milh  is  rapidly  coagulated.  Litmus  solution  is  decolorized  by 
the  production  of  large  quantities  of  acid. 

On  potato  the  growth  is  quite  characteristic.  It  is  very 
luxuriant,  forming  a  thick  moist  brown  layer  which  spreads 
rapidly  over  the  entire  surface  of  the  potato.  At  times  the 
rest  of  the  potato  is  discolored,  turning  distinctly  green. 

The  colon  bacillus  is  very  resistant  to  acids  and  antisep- 
tics. An  exposure  of  ten  minutes  to  a  temperature  of  60°  C. 
is  fatal. 

Pathogenesis  :  Although  Bacillus  coli  communis  is  ordinarily 
non-pathogenic    for   man,    it   is   not   infrequently   found    in 


BACILLUS  COLT  COMMUNIS.  285 

abscesses,  and  especially  in  suppurations  in  the  vicinity  of 
the  intestines.  It  is  believed  that  in  inflammatory  conditions 
of  the  intestinal  tract  the  organism  may  become  pathogenic. 
Immediately  after  death  it  is  found  in  all  the  tissues  of  the 
body.  When  injected  into  the  peritoneal  cavity  of  animals, 
death  results  in  from  eight  to  ten  days.  Cultures  of  the 
colon  bacillus  obtained  from  the  intestinal  discharges  of 
persons  suflPering  from  cholera  and  cholera  nostras  are  much 
more  virulent  than  those  obtained  from  pus  or  normal  feces. 
The  virulence  is  increased  by  rapid  passage  of  the  germ 
through  animals,  and  is  diminished  by  frequent  transplanta- 
tion. 

It  is  possible  to  immunize  animals  against  infection  with 
the  colon  bacillus  by  inoculating  them  with  gradually  increas- 
ing doses  of  either  dead  or  living  cultures. 

The  colon  bacillus  may  be  absorbed  from  the  intestinal 
canal  and  produce  inflammations  in  other  organs,  especially 
the  urinary  bladder,  the  gall-bladder,  and  all  the  biliary  chan- 
nels. Multiple  abscesses  of  the  liver  are  not  infrequently 
caused  by  the  colon  bacillus.  It  has  often  been  found  in  the 
intestinal  discharges  of  infants  suffering  with  cholera  infantum 
and  in  dysentery.  Other  infections  in  which  the  colon  bacil- 
lus has  been  found  in  large  numbers  are  meningitis,  solitary 
abscess  of  the  liver,  endocarditis,  bronchopneumonia,  ure- 
thritis, and  in  abscesses  of  the  skin  and  subcutaneous  tissues. 

McFarland  believes  that  the  colon  bacillus  is  not  a  single 
species  of  bacterium,  but  merely  a  name  applied  to  a  group 
of  organisms  whose  appearance  is  too  similar  to  permit  of 
their  differentiation.  This  group  is  usually  referred  to  as  the 
colon  group. 

The  method  of  differentiating  between  the  colon  and  typhoid 
bacilli  has  been  described  in  the  preceding  chapter,  but  it  may 
be  well  to  mention  again  points  of  difference : 

1.  The  colon  bacillus  is  shorter,  thicker,  less  motile,  and 
has  fewer  flagella  than  the  typhoid  bacillus. 

2.  Its  growth  is  more  rapid  and  very  luxuriant. 

3.  On  potato  it  forms  a  thick  brownish  membrane  which  is 
very  visible.  The  growth  of  the  typhoid  bacillus  is  colorless 
and  usually  invisible. 


286    ORGANISMS  RESEMBLING  BACILLUS  TYPHOSUS. 

4.  Its  growth  in  media  containing  sugar  is  accompanied 
by  tVip  pvolntipn  of  q^^  {|nr1  a  peculiar  odor. 

5.  Milk  is  coagulated  within  from  thirty-six  to  forty-eight 
hours.  The  color  of  litmus-milk  is  changed  to  red  because 
of  the  formation  of  acid. 

6.  In  nutrient  gelatin  or  agar  containing  lactose  and  litmus, 
and  of  a  slightly  alkaline  reaction,  the  colonies  of  the  colon 
bacillus  are  red,  those  of  the  typhoid  bacillus  blue. 

7.  When  grown  in  solutions  of  peptone  the  colon  bacillus 
produces  indol ;  the  typhoid  does  not. 

8.  The  colon  bacillus  grows  luxuriantly,  whereas  the  typhoid 
bacillus  does  not  grow  at  all,  in  asparagus  solutions. 

9.  The  colon  bacillus  gives  the  agglutination  reaction  with 
the  blood  of  animals  inoculated  with  this  bacillus,  but  not 
with  typhoid  blood.  Bacillus  typhosus  agglutinates  only  with 
typhoid  blood. 

Bacillus  Enteritidis. 

This  organism  was  cultivated  by^aertner  from  the  tissues 
of  a  cow  suffering  from  an  intestiiml  disease ;  and  from  the 
spleen  of  a  man  who  was  poisoned  by  eating  some  of  the  flesh 
of  the  cow. 

The  morphology  of  bacillus  enteritidis  is  almost  identical 
with  that  of  the  colon  bacillus. 

It  also  resembles  it  in  culture,  except  that  the  growth  on 
potato  is  white  or  yellowish-white.     It  does  not  produce  indol. 

It  is  differentiated  from  the  colo7i  bacillus  by  its  ability  to 
cause  infection  when  swallowed  and  the  absence  of  the  indol 
reaction.  It  differs  from  the  typhoid  bacillus  in  that  it  coagu- 
lates milk,  produces  acids  and  gases,  and  does  not  agglutinate 
with  typhoid  blood. 

Bacillus  Dysenteriae  (Shiga's  Bacillus). 

During  a  recent  epidemic  of  dysentery  in  Japan,  Shiga 
succeeded  in  isolating  a  characteristic  organism  from  the  intes- 
tinal discharges  of  dysentery  patients. 

Morphology  and  biology:  The  organism  belongs  to  the  colon 
group.     It  is  a  short,  thick  rod,  with  rounded  ends,  has  no 


BACILLUS  PARATYPHOSUS.  287 

flagella  and  is  not  motile.  Polar  granules  can  be  made  out 
when  the  germ  is  stained  with  methylene-blue.  Gram^s  stain 
is  not  applicable. 

Bacillus  dysenierice  develops  rapidly  at  the  body  tempera- 
ture, but  very  slightly  at  the  room  temperature.  The  culture- 
medium  should  be  slightly  alkaline,  as  the  bacillus  is  not  in 
the  least  resistant  to  acids. 

Both  deep  and  superficial  colonies  on  gelatin  plates  are  very 
small,  round  and  regular,  and  whitish  in  color.  The  medium 
is  not  liquefied. 

In  the  gelatin  stab  many  minute  grayish  colonies  develop 
along  the  track  of  the  needle  without  any  surface  growth. 

On  agar-agar  large  single,  bluish-white,  regular  colonies 
develop  at  the  end  of  twenty-four  hours.  There  is  no  growth 
on  blood-serum.  On  boiled  potato  the  growth  at  first  resembles 
that  of  the  typhoid  bacillus,  but  soon  takes  on  the  appearance 
of  the  growth  of  the  colon  bacillus  on  potato.  Bouillon  is 
clouded.  Milk  remains  unchanged.  The  organism  does  not 
produce  indol,  nor  does  it  evolve  gas  when  grown  on  media 
containing  sugar.     Acid-production  is  very  slight. 

Bacillus  dysentence  agglutinates  with  the  blood-serum  of 
persons  suffering  with  or  convalescent  from  dysentery. 

Shiga  has  obtained  an  immunizing  serum  from  horses  inocu- 
lated with  old  agar-agar  cultures  dried  in  vacuo,  and  has 
succeeded  in  reducing  the  mortality  from  34.7  to  9  per  cent. 
This  applies  only  to  cases  of  epidemic  dysentery,  and  not  to 
tropical  dysentery,  which  is  caused  by  an  animal  parasite, 
the  Amoeba  coli. 

Bacillus  Paratyphosus. 

It  has  hitherto  always  been  taken  for  granted  that  typhoid 
fever  may  differ  in  its  clinical  manifestations,  at  times  ap- 
pearing like  a  case  of  mild  or  abortive  typhoid.  Recently, 
however,  several  investigators  have  been  able  to  isolate  an 
organism  from  the  intestinal  discharges  and  blood  of  patients 
apparently  suffering  from  mild  forms  of  typhoid  fever,  which 
differs  from  both  the  typhoid  and  colon  ba(;illi,  and  also  from 
Shiga's  bacillus.  Nevertheless  it  is  a  member  of  the  colon 
group. 


288    OBGANISMS  RESEMBLING  BACILLUS  TYPHOSUS. 

This  organism  has  been  designated  as  the  paratyphoid  bacil- 
lus, and  is  accepted  as  the  specific  cause  of  paratyphoid  fever. 

Its  morphology  is  exactly  like  that  of  the  typhoid  bacillus. 

Its  growth  on  gelatin,  agar,  and  in  bouillon  is  also  the 
same  as  that  of  the  typhoid  cultures.  Indol-production  is 
either  absent  or  very  slight.  Litmus-milk  remains  unchanged. 
According  to  some  authorities,  therfe  is  a  terminal  alkalinity 
in  from  one  to  two  weeks.  The  organism  does  not  aggluti- 
nate with  typhoid  blood,  but  does  with  the  blood  of  persons 
suiTering  with  paratyphoid  fever. 

The  bacillus  is  a  very  short  rod  with  rounded  ends,  and  has 
from  ten  to  twelve  terminal  and  lateral  flagella.  It  is  actively 
motile.  It  is  also  identical  with  Bacillus  psittacosis^  which 
was  discovered  and  isolated  by  Nocard. 

During  an  epidemic  of  infectious  pneumonia  Widal  found 
the  paratyphoid  bacillus  in  an  abscess  in  the  neighborhood 
of  the  thyroid  gland.  It  has  also  been  called  the  paracolon 
bacillus  and  bacillus  0. 

Further  investigations  are  necessary  in  order  to  give  us  a 
more  complete  history  of  this  organism. 


CHAPTER  XIII. 

YELLOW  FEVER;  BUBONIC  PLAGUE;  INFLUENZA. 

Bacillus  Icteroides    (Bacillus  of  Yellow  Fever). 

In  1897  Sanarelli  found  a  bacillus  in  the  tissues  and  blood 
of  yellow  fever  patients,  Avhich  he  claimed  to  be  the  specific 
cause  of  yellow  fever.  Sternberg,  in  1889,  isolated  an  organ- 
ism from  the  intestinal  contents  and  the  liver  of  yellow  fever 
cadavers,  which  he  termed  Bacillus  X  or  Bacillus  cuniculicida 
Havaniensis.  He  was  convinced  of  the  identity  of  his  germ 
with  that  of  Sanarelli's  Bacillus  icteroides.  In  both  instances 
Bacillus  coll  communis  was  also  present  in  large  numbers. 

Morphology  and  biology :  Bacillus  icteroides  is  an  exceed- 
ingly short  rod  with  rounded  ends,  usually  occurring  singly, 
but  sometimes  associated  in  pairs  (Fig.  130).  In  culture  it 
has  been  seen  to  form  short  filaments.  It  very  closely  resem- 
bles the  colon  bacillus,  but  is  somewhat  larger,  measuring 
from  1  //  to  3  [i  in  length,  and  from  0.8  [jl  to  1  [jl  in  width. 
It  is  actively  motile,  but  has  no  flagella.  It  does  not  form 
spores.  The  anilin  dyes  stain  it  rapidly ;  Gram's  method  is 
not  applicable. 

Bacillus  icteroides  is  a  facultative  anaerobe,  growing  on  all 
the  various  culture-media  at  either  the  room  or  body  tem- 
perature, but  best  at  the  latter. 

On  gelatin  plates  it  forms  small,  rounded,  transparent, 
intensely  granular  colonies,  the  centre  of  which  soon  becomes 
very  much  darker  than  the  periphery.  The  gelatin  is  not 
liquefied.  In  bouillon  neither  a  precipitate  nor  a  surface 
membrane  is  formed.  On  blood-serum  the  growth  is  almost 
imperceptible.     The  growth  on  potato  is  invisible. 

The  growth  on  ihe  agar-agar  slant  is  spoken  of  as  being 
characteristic,  providing  the  temperature  does  not  exceed 
22°  C.     Higher  temperatures   appear   to   interfere  with  the 

19— Bact.  289 


290     YELLOW  FEVER;  BUBONIC  PLAGUE;  INFLUENZA. 

development  on  the  agar  in  a  distinctive  manner.  Sanarelli 
advises  an  exposure  of  from  twelve  to  sixteen  hours  to  the 
incubator  temperature,  and  then  an  exposure  to  the  room 
temperature  for  the  same  length  of  time.  The  colonies  look 
like  a  drop  of  milk.  They  are  transparent  and  bluish,  with 
a  dark  centre  like  a  nucleus. 

Glucose  and  saccharose  are  fermented.  Indol  is  formed 
in  solutions  containing  peptone.  Milk  remains  unchanged. 
Bacillus  icteroides  lives  for  a  long  time  in  sea-water,  but  dies 

Fig.  130. 


Bacillus  icteroides.    (Sanarelli.) 


quickly  in  ordinary  water.  It  succumbs  to  light,  but  resists 
desiccation. 

Sternberg^  Bacillus  X  stains  with  Gram's  stain  and  pro- 
duces a  luxuriant  growth  on  potato  ;  otherwise  it  is  apparently 
identical  with  Bacillus  icteroides. 

Pathogenesis :  Bacillus  ictei^oides  is  pathogenic  for  both  man 
and  animals.  When  injected  into  the  ear  vein  of  an  animal, 
it  produces  the  identical  lesions  seen  in  yellow  fever  cadavers. 
According   to  Sanarelli,   infection   takes   place   through   the 


BACILLUS  ICTEBOIDES.  291 

respiratory  tract,  and  not  through  the  gastro-intestinal  tract, 
as  is  commonly  supposed.  He  suggests  that  moulds  may 
protect  Bacillus  icter^oldes  and  furnish  nourishment,  especially 
in  damp  places  like  the  hold  of  a  ship.  The  bacillus  pro- 
duces a  toxin.  Animals  immune  to  yellow  fever,  or  whose 
susceptibility  is  not  very  great,  are  not  affected  by  this  toxin. 
Sanarelli  found  that  the  injection  into  man  of  small  quantities 
of  a  filtered  culture  of  Bacillus  icteroides  was  followed  by  a 
typical  attack  of  yellow  fever. 

Sanarelli  has  also  prepared  a  curative  serum,  which  he  calls 
antiamarylic  serum.  It  is  not  an  antitoxin,  but  only  a  germi- 
cide, thus  making  its  administration  useless  in  those  cases  in 
which  a  large  amount  of  toxin  has  been  produced.  It  must 
be  used  early,  before  any  considerable  amount  of  toxin  has 
been  elaborated  and  absorbed.  The  serum  has  not,  as  yet, 
been  tested  sufficiently  to  warrant  the  expression  of  a  positive 
opinion  as  to  its  curative  value. 

Infection :  Laboratory  experiments  and  clinical  researches 
have  positively  established  the  fact  that  the  mosquito,  the 
variety  Anopheles^  is  the  most  important,  if  not  the  only 
source  or  method  by  which  the  infection  in  yellow  fever  is 
conveyed.  This  mosquito  bites  the  yellow  fever  patient,  and 
then  by  again  biting  a  well  person  carries  the  infecting  germ 
from  the  sick  to  the  well.  There  are  two  periods  when  the 
bite  of  the  mosquito  is  dangerous  :  first,  shortly  after  it  has 
bitten  a  yellow  fever  patient,  when  its  sucking  apparatus  still 
contains  the  germ-laden  blood  ;  second,  after  the  germs  have 
developed  sufficiently  within  the  body  of  the  mosquito  so  that 
its  salivary  organs  contain  the  specific  germ.  In  the  first 
case,  the  course  of  the  disease  is  a  rather  mild  one,  and  in  the 
second  very  severe.  One  observer  asks  whether  this  might 
not  be  of  some  value  clinically  in  producing  immunity  to 
yellow  fever  by  a  mild  attack  of  the  disease.  One  attack 
confers  positive  immunity. 

While  a  number  of  investigators  have  confirmed  the  claims 
of  Sanarelli  that  Bacillus  icteroides  is  the  specific  cause  of 
yellow  fever,  others  are  inclined  to  believe  that  it  is  simply 
one  of  the  many  associated  organisms  so  frequently  found  in 
the  lesions  of  yellow  fever. 


292     YELLOW  FEVER;  BUBONIC  PLAGUE;   INFLUENZA. 

F.  Novy  made  a  careful  analysis  of  Sanarelli's  findings, 
and  came  to  the  conclusion  that  Bacillus  icte7'oides  is  not  the 
cause  of  yellow  fever.  His  principal  objection  is  based  on 
the  fact  that  yellow  fever  is  stopped  at  the  appearance  of  a 
frost,  whereas  Bacillus  icteroldes  is  not  injured  in  the  least  by 
cold  of  even  a  greater  degree  than  that  causing  a  frost.  In 
the  absen(;e  of  any  germ  which  more  nearly  complies  with 
the  laws  of  specificity  than  does  Bacillus  icteroldes,  we  believe 
that  it  is  proper  to  regard  Bacillus  icteroldes  as  the  specific 
cause  of  the  disease. 


Bubonic  Plague  (Bacillus  Pestis  Bubonicae;  Bacterium  Pestis). 

The  specific  cause  of  bubonic  plague  was  discovered  in  1 894 
by  Kitasato  and  Yersin.  The  bacillus  of  plague  is  found  in 
the  pus  obtained  from  the  suppurating  lymph-glands,  in  the 
sputum  in  cases  of  bubonic  pneumonia,  in  the  feces,  and  occa- 
sionally in  the  blood  and  internal  organs. 

Morphology  and  biology:  Bacterium  pestis  is  a  very  short 
and  stubby-looking  bacillus,  with  rounded  ends.  A  capsule 
may  at  times  be  demonstrated.  The  bacillus  is  extremely 
variable  in  culture.  At  times  it  appears  to  be  a  diplococcus 
or  an  oval  coccus;  at  other  times  short  chains  are  formed. 
Curved  rods,  clubs,  and  odd  forms  are  seen  in  cultures  the 
vitality  of  which  is  almost  exhausted  (Fig.  131).  The  plague 
bacillus  does  not  form  spores,  although  it  exhibits  polar  gran- 
ules when  stained  with  methylene-blue.  It  does  not  stain  by 
Gram\s  method.     It  has  no  flagella  and  is  not  motile. 

It  is  strongly  aerobic,  and  grows  well  on  all  the  usual 
culture-media  at  both  the  room  and  body  temperature. 

On  gelatin  plates  the  colonies  are  granular  with  a  regular 
border,  and  brownish  in  color.  The  gelatin  is  not  liquefied. 
In  gelatin  stabs  a  slight  whitish  growth  is  formed  on  the  sur- 
face and  along  the  line  of  inoculation.  A  grayish-white 
surface  growth  is  formed  on  glycerln-agar.  In  bouillon  a 
coarse  granular  deposit  forms  on  the  sides  of  the  tube,  the 
fluid  remaining  clear.  On  potato  a  thin  white  pellicle  covers 
the  surface  of  the  potato.  On  blood-serum  a  luxuriant  moist 
whitish  growth  is  formed. 


BUBONIC  PLAGUE. 


293 


The  plague  bacillus  does  not  form  indol,  nor  does  it  fer- 
ment.    A  slight  amount  of  oxid  is  formed. 

Vitality :  A  temperature  of  55°  C.  kills  the  germ  in  ten 
minutes ;  1  :  1000  bichloride  kills  immediately  ;  and  1  per 
cent,  carbolic  acid  or  lysol  solution  in  ten  minutes.  Weak 
solutions  of  the  mineral  acids  are  rapidly  destructive.  The 
bacillus  does  not  resist  drying,  nor  does  it  survive  transplan- 
tation to  either  sterilized  or  non-sterilized  water  for  any  length 
of  time. 

Pathogenesis:  The  plague  bacillus  is  pathogenic  for  man 
and  for  animals,  especially  the  rodent,  which  is  the  usual  cause 

Fig.  131. 


Bacillus  of  bubonic  plague.    (Yersin.) 


of  widespread  epidemics  of  plague.  The  rat  acquires  the  dis- 
ease by  eating  plague-infected  food  or  the  bodies  of  animals 
dead  of  plague.  When  the  animal  sickens,  it  usually  seeks 
refuge  in  some  dark  place,  like  the  cellar  of  a  house  or  the 
hold  of  a  ship,  where  it  dies.  In  this  way  infection  is  carried 
from  place  to  place  and  over  great  distances  in  an  incredibly 
short  time.  Such  houses  and  ships  become  known  as  plague- 
houses  or  plague-ships;  and  the  disease  may  remain  limited 
to  its  boundaries  unless  the  persons  infected  with  the  disease 
are  carried  to  other  places. 


294     YELLOW  FEVER;  BUBONIC  PLAGUE;  INFLUENZA. 

Infection :  The  plague  bacillus  usually  gains  entrance  to 
the  body  through  slight  injuries  of  the  sJcirij  although  the 
organism  may  be  inhaled  and  lodge  in  the  lung.  The  injury 
of  the  skin  may  be  imperceptible  and  the  infection  atria  may 
be  very  numerous.  Insect-bites  may  be  the  source  of  infec- 
tion. At  the  site  of  infection  a  localized  suppuration  devel- 
ops, which  spreads  along  the  lymphatics  to  the  nearest  chain 
of  glands.  These  glands  swell  up,  and  finally  suppurate  and 
form  buboes,  from  which  the  disease  has  its  name  of  bubonic 
plague. 

In  mild  cases  the  infection  does  not  spread  further ;  but 
in  severe  cases  the  lymph-glands  in  remote  parts  of  the  body 
are  also  affected.  The  bacilli  may  finally  make  their  way  into 
the  blood-current,  and  from  there  to  all  parts  of  the  body. 

When  infection  occurs  through  the  i^espiratory  tract,  a 
typical  pneumonia  is  produced.  The  plague  bacilli  are  found 
in  the  sputum,  and  may  be  associated  with  the  streptococcus 
and  diplococcus.  Tonsillar  infection  has  also  been  observed. 
When  infection  occurs  in  that  wav,  the  disease  is  rapidly 
fatal. 

Prophylaxis  :  In  the  prophylaxis  of  plague  general  hygienic 
precautions  are  of  first  importance :  Properly  ventilated 
dwellings ;  personal  cleanliness ;  prompt  surgical  care  of  any 
wounds  or  insect-bites ;  the  careful  avoidance  of  anything 
suggestive  of  filth ;  the  immediate  disposition  of  all  dead 
rats,  especially  in  plague-infected  localities ;  and  the  destruc- 
tion of  as  many  live  rats  as  possible.  The  patient  should  be 
isolated  and  watched,  so  that  the  infection  does  not  spread  to 
the  attendants  or  members  of  the  family.  The  bodies  of 
persons  dead  of  plague  should  be  disposed  of  very  j^romptly 
after  thorough  disinfection.  Cremation  is  the  best  and  most 
thorough  method  of  disposition. 

Immunization  :  Susceptible  animals  can  be  immunized  with 
dead  cultures  of  the  plague  bacillus.  Haffkine^s  protective 
inoculation  against  plague  consists  of  the  injection  of  0.5  to 
2.5  c.c.  of  a  devitalized  culture  of  the  plague  bacillus.  The 
injection  is  repeated  after  eight  or  ten  days.  Yersin  immu- 
nizes animals  by  the  intravenous  or  intraperitoneal  injection 
of  dead   cultures   or  by   repeated    subcutaneous   inoculation. 


INFLUENZA.  295 

The  serum  of  animals  immunized  in  this  way  with  virulent 
cultures  also  protects  other  susceptible  animals.  The  serum 
is  both  antitoxic  and  bactericidal.  The  immunity  conferred 
by  either  of  these  methods  is  usually  only  of  short  duration 
— about  one  month ;  and  is  therefore  used  only  as  a  protective 
during  an  epidemic. 

The  mortality  from  plague  has  been  reduced  considerably 
by  these  methods,  and  better  results  are  to  be  expected  with 
the  perfection  of  immunization  by  cultures  of  the  bacillus. 

Diagnosis :  The  plague  bacillus  can  always  be  obtained  in 
large  numbers  from  the  suppurating  lymph-glands,  from  the 
sputum  of  plague  pneumonia,  and  by  puncture  from  the 
swollen  but  intact  lymph-glands.  In  cases  of  plague  septi- 
caemia the  organism  is  found  in  the  circulating  blood  and  in 
the  organs. 

The  films  are  stained  with  methylene-blue,  when  the  char- 
acteristic polar  staining  is  seen.  The  bacilli  very  often  look 
like  diplococci  because  of  the  intensity  of  the  staining  of 
these  polar  bodies. 

Oultures  are  made  from  material  obtained  from  the  lesions, 
which  is  spread  in  a  thin  layer  on  gelatin  plates.  The  plague 
bacillus  also  agglutinates  with  the  blood-serum  of  persons  or 
animals  that  have  recovered  from  the  disease.  This  aggluti- 
nation does  not,  however,  occur  before  the  second  week,  and 
is  most  marked  in  the  second  and  third  weeks. 

Influenza  (Bacillus  Influenzae — Bacillus  of  Pfeiffer). 

The  specificity  of  this  germ  was  established  by  Pfeiffer  in 
1892,  when  he  succeeded  in  isolating  and  making  pure  cult- 
ures of  Bacillus  influenzae  from  the  bronchial  secretions  of 
influenza  patients.  His  findings  have  been  confirmed  by 
others,  and  the  organism  is  accepted  as  the  specific  cause  of 
influenza.  The  peculiar  shape  of  the  germ  interfered  with 
its  earlier  discovery. 

Morphology  and  biology :  Bacillus  influenzce  is  a  short,  thick 
rod,  with  rounded  ends.  It  is  so  short  and  thick  that  when 
two  germs  are  placed  end  to  end  they  resemble  Diplococcus 
pneumoniae.     The  occurrence  usually  is  single,  but  may  be 


296     YELLOW  FEVER;   BUBONIC  PLAGUE:  INFLUENZA, 

in  pairs  or  in  short  chains  of  three  or  four  members  (Fig. 
132).  Long  chains  are  occasionally  seen  in  very  old  cult- 
ures. The  organism  does  not  form  spores,  is  not  motile,  and 
has  no  flagella. 

The  anilin  dyes  stain  only  after  a  very  long  exposure  of 
the  film  to  the  stain.  When  stained  with  Loeffler's  alkaline 
methylene-blue,  polar  granules  can  be  made  out  in  some  of 
the  organisms.     Certain   it   is  that  Bacillus  infiuenzce  stains 

Fig.  132. 


Influenza  bacilli.    X  1100.    (Park.) 

more  heavily  at  its  ends  than  in  the  middle.  Gram's  stain 
decolorizes  the  germ.  Czenzyiike^s  stain  is  the  best  for  stain- 
ing the  bacillus  in  blood-films.     It  is  made  as  follows : 

Concentrated  aqueous  solution 

of  methylene-blue,  40  parts ; 

Solution  of  eo'sin  (0.5  per  cent.) 

in  70  per  cent,  alcohol,  20     " 

Distilled  water,  40     " 

The  preparation  is  placed  in  this  solution  for  from  three  to 
six  hours,  and  is  then  well  washed  in  water,  dried,  and 
mounted  in  balsam.     The  red  corpuscles  are  stained  red,  the 


INFLUENZA.  297 

leucocytes  blue,  and  the  bacillus  is  also  stained  blue,  appear- 
ing as  a  short,  thick  rod  ;  or  dumb-bell. 

Desiccation  is  rapidly  fatal ;  also  a  five  minutes'  exposure  to 
a  temperature  of  60°  C. 

Bacillus  influenzae  develops  rapidly  at  the  body  temperature, 
but  best  at  a  temperature  slightly  lower  than  this.  It  is 
strongly  aerobic,  and  will  not  grow  in  the  total  absence  of  oxy- 
gen. It  does  not  form  any  growth  on  ordinary  media,  but 
develops  luxuriantly  on  blood-serum  or  on  any  medium  the  sur- 
face of  which  has  been  smeared  with  blood,  haemoglobin,  or  leu- 
cocytes. It  is  easily  obtained  from  the  sputum  or  nasal  mucus, 
and  also  from  the  throat  of  persons  suffering  with  influenza. 

On  media  appropriate  for  its  development  very  small  pearly 
colonies  appear  within  forty-eight  hours.  They  are  shining, 
moist  and  transparent,  and  may  easily  escape  notice  at  first. 
They  frequently  have  the  appearance  of  a  small  opalescent 
drop  of  water.  Old  colonies  turn  yellowish  brown.  The 
colonies  rarely  become  confluent. 

Pathogenesis:  The  influenza  bacillus  is  apparently  patho- 
genic for  man  only,  as  it  has  so  far  been  impossible  to  pro- 
duce the  typical  disease  in  animals  by  inoculation.  When 
inoculated  with  a  large  quantity  of  the  culture  animals  die 
with  symptoms  of  intense  intoxication. 

In  man  infection  probably  takes  place  through  the  air- 
passages,  in  which  the  previous  condition  of  the  lining  mucosa 
is  of  importance.  The  bacillus  cannot  withstand  desiccation, 
but  when  contained  in  a  plug  of  mucus  it  remains  alive  for  a 
considerable  period  of  time.  The  secretions  from  the  mucous 
membranes  are  the  means  of  spreading  the  disease.  Cough- 
ing or  sneezing  forces  the  infected  mucus  out  of  the  patient's 
nose  or  throat,  and  the  disease  is  thus  conveyed  directly  to 
other  individuals. 

It  has  been  suggested  that  air-currents  carry  the  disease  for 
miles  from  the  original  seat  of  the  disease.  Severe  epidemics 
of  the  disease,  separated  perhaps  hundreds  of  miles,  have 
been  accounted  for  in  this  way.  The  probability  is,  however, 
that  if  the  origin  of  such  epidemics  is  carefully  looked  into, 
it  will  be  found  that  some  individual  who  is  convalescent 
from  influenza  was  really  the  carrier  of  the  disease. 


298     YELLOW  FEVER;  BUBONIC  PLAGUE;  INFLUENZA. 

The  bacilli  may  remain  latent  in  the  secretions  for  months 
after  recovery  from  the  disease  has  apparently  been  complete, 
and  under  favorable  conditions  again  become  virulent. 

Immunity :  One  attack  of  influenza  undoubtedly  confers 
immunity,  but  unfortunately  it  is  of  short  duration.  In  fact, 
it  would  appear  that  when  the  immunity  has  disappeared  the 
individual  is  even  more  susceptible  to  the  disease  than  before 
the  first  attack.  Persons  have  been  attacked  several  times 
during  the  course  of  the  same  epidemic.  Owing  to  the  insus- 
ceptibility of  animals  to  influenza,  it  has  been  impossible  to 
immunize  them,  and  thus,  perhaps,  obtain  a  serum  which 
could  be  used  for  immunizing  or  curative  purposes. 

The  bacillus  is  responsible  for  the  lesions,  and  is  always 
found  at  the  seat  of  the  disease ;  it  does  not  produce  a  toxin 
which  is  absorbed. 

Diagnosis  :  The  bacteriologic  diagnosis  is  readily  made  from 
the  nasal  secretions  and  the  bronchial  mucus.  A  slide  can 
be  prepared,  stained,  and  examined  immediately.  The  pecu- 
liar appearance  of  the  germ  and  its  behavior  to  stains  are 
absolutely  characteristic.  Cultures  may  be  made  on  blood- 
serum  or  other  media  smeared  with  blood,  haemoglobin,  or 
sputum,  which  always  contains  corpuscles. 

It  should  be  borne  in  mind  that  the  influenza  bacillus  may 
be  the  cause  of  conditions  other  than  those  which  are  looked 
upon  as  distinctive  of  this  disease.  During  severe  epidemics 
of  influenza  it  is  not  uncommon  to  see  typical  cases  of  lobar 
pneumonia  which  are  due  to  the  influenza  bacillus  and  not  to 
the  pneumococcus.  It  is  important  to  determine  the  cause 
of  such  a  pneumonia,  as  it  will  influence  the  treatment  con- 
siderably. The  serum  treatment  of  pneumonia  could  not  be 
used  in  influenza  pneumonia,  and  the  prognosis  in  the  latter 
is  much  worse  than  in  a  pneumococcus  pneumonia. 

The  influenza  bacillus  may  be  confounded  with  another 
organism  which  Pfeiifer  found  in  the  sputum  of  cases  of 
bronchopneumonia,  and  which  he  named  the  pseudo-influenza 
bacillus.  This  organism  differs  in  culture  in  that  it  exhibits 
a  marked  tendency  to  form  very  long  filaments.  It  is  also 
somewhat  longer  than  the  true  bacillus.  Otherwise  the  re- 
semblance between  the  two  is  very  close. 


CHAPTEE   XIV. 

ANTHRAX;   AND   HYDROPHOBIA. 

Bacillus  Anthracis. 

The  specific  cause  of  anthrax  was  one  of  the  first  bacteria 
which  was  proved  to  be  an  etiologic  factor  in  the  production 
of  disease.  Bacilhis  anthracis  has  served  as  a  basis  for  most 
bacteriologic  studies  which  have  been  made  since  its  dis- 
covery.    It  was  detected  as  early  as  1849  in  the  blood  of 

Fig.  133. 


Anthrax  bacillus :  agar  culture.    X  900.    (Park.) 

animals  suffering  w^th  anthrax,  but  was  not  successfully  cul- 
tivated until  1876.  The  disease  is  usually  referred  to  as 
splenic  fever. 

Morphology  and  biology :  The  anthrax  bacillus  is  a  long, 
slender  rod,  with  squared  ends,  sometimes  slightly  concave. 

299 


300 


ANTHRAX:  AND  HYDROPHOBIA. 


It  is  from  5  //  to  20  /i  long,  and  from  1  /i  to  1.5 /i  thick.  The 
organism  usually  forms  very  long  chains  or  filaments,  which 
interlace  very  freely,  twisting  in  and  out  like  a  skein  of 
wool  (Fig.  133).  The  individual  members  of  the  chain  can 
be  identified  as  a  rule.  Sometimes  one  or  both  ends  of  the 
germ  are  slightly  enlarged  or  swollen,  so  that  the  chain  pre- 
sents nodular  thickenings  at  intervals.  These  nodules  and 
concave  ends  are  seen  most  frequently  in  culture  specimens. 
The  thin  transparent  capsule  surrounding  the  germ  can  be 
seen  when  it  is  stained  by  Johne's  method. 

Fig.  134. 


Spores  heavily  stained.    Bodies  of  disintegrating  bacilli  faintly  stained. 
X  1000.     (Park.) 


The  anthrax  bacillus  is  not  motile,  and  it  has  no  flagella. 
Spores,  large  and  shining,  are  formed  rapidly  in  the  presence 
of  oxygen.  These  spores  are  oval  in  shape,  and  each  bacillus 
usually  has  only  one.  As  the  spore  increases  in  size  the  par- 
ent cell  is  seen  to  disappear  gradually  until  the  spore  is  finally 
set  free  (Fig.  134).     The  bacillus  is  strongly  aerobic. 

Bacillus  anthracis  is  stained  by  the  ariilin  dy^es,  and  also  by 
Gram's  method.  When  contained  in  tissue  it  is  stained  with 
methylene-blue,  the  tissue  with  carmine,  or  with  Gram's  stain, 
or  a  combination  of  Gram's  and  Weigert's  stains,  picrocar- 


BACILLUS  ANTHRACTS. 


301 


mine,  or  picrocarmine  and  Gram.  The  spores  are  stained  as 
previously  described.  Owing  to  their  size  and  affinity  for 
stains,  these  spores  are  specially  adapted  for  the  study  of 
sporulation.  Bacilli  have  been  described  that  do  not  sporu- 
late. 

The  anthrax  bacillus  is  easily  cultivated  on  all  kinds  of 
media  and  between  a  temperature  of  14°  and  43°  C.  The 
temperature  of  the  body  is  most  conducive  to  sporulatioi« 

Fig.  135. 


'^f^fj^-' 


Colonies  of  Bacilhts  anthracis  upon  gelatin  plates,    a,  at  the  end  of  twenty-four 
hours ;  b,  at  the  end  of  forty-eight  hours.    X  80.    (F.  Fluegge.) 


The  colonies  on  gelatin  plates  are  absolutely  characteristic. 
Within  twenty-four  hours  opaque  grayish  colonies  develop 
(Fig.  135).  The  border  of  the  colony  is  extremely  irregular 
and  much  lighter  in  color  than  the  centre.  As  the  colony 
increases  in  age  the  irregularity  of  the  border  becomes  more 
marked  until  the  colony  finally  has  the  appearance  of  a  badly 
snarled  mass  of  threads.  The  gelatin  is  slightly  liquefied. 
The  colonies  are  examined  with  a  low-power  lens  or  by  mak- 
ing a  Klatsch  preparation.  They  are  very  large  when  fully 
develo])ed. 


302  ANTHRAX;  AND  HYDROPHOBIA. 

A  stab  culture  in  gelatin  develops  quite  rapidly  and  luxuri- 
antly on  the  surface  jind  along  the  track  of  the  needle.  From 
this  whitish  linear  growth  numerous  fine,  hair  like  projections 
extend  out  into  the  medium.  Liquefaction  begins  at  the  sur- 
face, and  is  complete  within  a  few  weeks,  when  the  growth  is 
precipitated. 

The  growth  on  agar-agar  plates  is  the  same  as  that  on 
gelatin  plates,  but  more  distinct.  The  medium  is  not  lique- 
fied. Agar  stroke  cultures  are  not  at  all  characteristic.  A 
thin  wrinkled  layer,  with  irregular  edges,  forms  along  the 
line  of  inoculation,  and  a  few  fine  threads  project  from  the 
central  growth.  Sporulation  occurs  most  rapidly  on  agar- 
agar.     In  old  cultures  the  medium  is  turned  a  deep  brown. 

In  bouillon  development  is  quite  rapid,  the  growth  forming 
in  small  flaky  masses  which  rapidly  settle  to  the  bottom  of 
the  tube,  leaving  the  supernatant  fluid  perfectly  clear. 
Growth  on  blood-serum  is  very  sparse ;  the  medium  is  slightly 
liquefied.  On  potato  a  thick  dry  white  membrane  is  formed. 
All  the  culture-media  should  be  slightly  alkaline,  as  the 
anthrax  bacillus  will  not  grow  in  the  presence  of  even  a  very 
small  quantity  of  free  acid. 

Vitality  :  One  of  the  characteristics  of  the  anthrax  bacil- 
lus, and  especially  its  spores,  is  the  resistance  to  heat  and 
chemicals.  The  mature  bacilli  can  withstand  a  temperature 
of  60°  C.  for  fifteen  minutes.  The  spores  survive  live  steam 
at  a  temperature  of  100°  C.  for  from  ten  to  fifteen  minutes ; 
compressed  steam,  for  five  minutes.  A  5  per  cent,  solution 
of  carbolic  acid  kills  the  bacillus  in  ten  seconds,  and  the 
s])ore  in  from  thirty-five  to  forty  days.  A  1  :  1000  solution 
of  bichloride  destroys  the  spores  in  about  twenty  hours. 
When  kept  in  sterilized  water  the  spores  live  for  many 
months,  but  the  bacillus  dies  in  about  three  days.  The  bacil- 
lus is  not  able  to  resist  putrefaction,  but  the  spores  retain 
their  vitality. 

Pathogenesis :  Anthrax  is  a  disease  of  animals,  but  is  met 
with  in  man  when  the  individual  comes  in  contact  with 
anthrax  infected  animals.  Shepherds,  tanners,  and  butchers 
are  especially  predisposed  to  the  infection  because  of  their 
occupation,  which  necessitates  handling  of  the  carcass,  and 


PLATE    VI. 


(QJ 


'hi 


ii 


Two  cultures  of  anthrax  bacilli  prepared  from  the  same  material 
at  the  sam.e  time.     (Senn.) 


a.  With  a  pressure  of  4  cm.  of  mercury. 

b.  With  atmospheric  pressure. 


BACILLUS  ANTHRACIS.  303 

especially  the  hide.  Even  tanning  of  the  hides  does  not  lessen 
the  danger  of  infection.  Leather- workers,  brush-makers,  and 
others  handling  the  finisTied^roducT,  Tiave  been  known  to 
become  infected  with  anthrax. 

A  very  forcible  illustration  of  the  extreme  infectiousness  of 
the  body  of  an  animal  dead  of  anthrax  is  mentioned  by 
Eineke.  An  ox  died  of  anthrax.  Two  persons  who  ate  of 
the  meat  of  this  animal  also  died  of  anthrax.  The  hide  of 
the  animal  was  macerated  in  a  small  lake,  and  was  finally 
worked  up  by  a  harness-maker,  who  was  immediately  attacked 
by  the  disease.  Two  horses  wearing  halters  made  from  the 
hide  also  fell  victims  to  the  disease.  Of  a  herd  of  sheep 
bathing  in  the  lake,  twenty  were  attacked  by  anthrax  (Levy 
and  Klemperer). 

Portal  of  infection :  The  most  frequent  portal  of  infection 
is  the  skin,  either  through  an  injury  or  the  bite  of  an  insect 
which'  has  fed  on  the  anthrax  cadaver.  If  the  injury  is 
minute,  a  "  carbuncle ''  speedily  develops  at  the  site  of  infec- 
tion. This  IS  usually  known  as  malignant  pustule,  a  form  of 
"  external  anthrax.''  It  is  rarely  accompanied  by  a  general 
infection.  If  the  injury  is  a  regular  wound,  there  follows  a 
local,  spreading  infection  known  as  ^'anthrax  oedema^''  the 
other  form  of  "external  anthrax,"  that  is  always  accom- 
panied by  a  general  infection  which  is  usually  fatal. 

Anthrax  infection  occasionally  occurs  through  the  (jastro- 
intestinal  canal.  Partaking  of  the  food  of  animals  dead  of 
anthrax  is  invariably  followed  by  a  general  infection  and  sep- 
ticaemia which  are  fatal.  The  pasturage  of  the  animal  may 
have  become  infected  with  anthrax  through  the  burial  of  an 
anthrax  cadaver.  The  spores  remain  alive  in  the  soil  for 
years,  and  thus  may  infect  animals  grazing  on  this  ground. 
Pasteur  was  of  the  opinion  that  the  earth-worm,  feeding  on 
the  anthrax  cadavers,  carried  the  spores  to  the  surface  and 
deposited  them  there  with  their  excreta. 

Snails,  flies,  and  other  insects  may  also  be  instrumental  in 
dissemination  of  the  spores.  The  gastro-intestinal  infection 
in  man  has  been  described  as  an  intestinal  mycosis.  The 
symptoms  caused  by  such  an  infection  are  similar  to  those 
of  typhoid  or  dysentery.     In  some  instances  the  anthrax  ba- 


304  ANTHRAX;  AND  HYDROPHOBIA. 

cillus  passes  through  the  intestinal  wall  without  producing 
disease. 

Gastro-intestinal  anthrax  infection  and  wool-sorters'  dis- 
ease are  forms  of  "internal  anthrax.'^ 

The  so-called  wool-sorters'  disease  is  an  infection  with  the 
anthrax  bacillus,  or  its  spores,  occurring  through  the  respira- 
tory tract  as  a  result  of  the  sorting  or  picking  of  infected  wool. 

In  all  forms  of  "anthrax"  with  a  general  infection,  the 
bacilli  are  found  in  the  blood,  and  especially  in  the  internal 
organs,  such  as  the  liver,  spleeUj  and  lungs.  The  accumula- 
tion of  a  large  number  of  anthrax  bacilli  in  the  capillary 
vessels  is  a  not  infrequent  (;ause  of  thrombosis  and  rupture 
of  the  vessel.  Late  in  the  disease  the  bacillus  is  also  found 
in  the  urine,  bile,  and  feces. 

The  organisms  are  not  very  numerous  in  a  malignant  pus- 
tule. If  death  occurs  it  is  due  to  a  general  infection  and 
septicaemia. 

Heredity :  Transmission  from  the  mother  to  the  foetus  has 
been  described.  Intra-uterine  infection  was  described  by 
Marchand.  One  observer  infected  the  rabbit's  foetus  in  utero. 
If  the  mothers  escaped  the  disease,  they  were  immune  for 
some  time  afterward. 

Immunity  :  One  attack  of  anthrax  confers  a  very  temporary 
immunity.  It  is  possible  to  immunize  animals  experimentally. 
Pasteur  manufactured  two  varieties  of  vaccine  from  attenu- 
ated anthrax  bacilli  and  succeeded  in  immunizing  rabbits. 
He  found  that  such  injections  conferred  absolute  immunity  to 
a  subsequent  subcutaneous  inoculation  of  the  animal  with 
anthrax.  But  the  blood-serum  of  these  animals  so  immunized 
did  not  have  the  power  to  confer  immunity  to  other  animals. 

Prophylaxis :  Prophylaxis  against  anthrax  consists  in  thor- 
ough disinfection  of  the  bodies  of  animals  and  men  dead  of 
the  disease ;  their  complete  isolation  while  sick ;  and  careful 
disinfection  of  all  the  excreta  and  discharges.  The  best 
disinfection  of  the  dead  body  is  incineration.  This  will  com- 
pletely eliminate  the  possibility  of  infection  from  that  par- 
ticular body.  Suspicious  hides  should  be  thoroughly  disin- 
fected before  they  are  handled  in  any  way. 

Diagnosis :  An  examination  of  the  blood  or  of  the  material 


PLATE    VII. 


^    1®  A®  *\*  \*^ 

1l^ 


'%,"V, 


\  -c^  ■#  %  -}■ 


Anthrax  bacilli  in  liver  of  mouse. 

X  about  450  diameters.     Bacilli  stained  by  Gram's  method 
tissue  stained  with  Bismarck-brown.     (Abbott.) 


BACILLUS  OF  SYMPTOMATIC  ANTHRAX,  305 

obtained  from  a  malignant  pustule,  or  the  sputum  of  cases 
suffering  from  pulmonary  anthrax,  will  always  reveal  the 
characteristic  bacilli,  perhaps  showing  spores,  and  arranged 
in  long  chains  which  may  be  more  or  less  twisted  (see  Fig. 
125).  The  characteristic  growth  on  the  gelatin  plates  and  the 
gelatin  stab  will  confirm  the  diagnosis. 

When  for  sanitary  purposes  it  is  necessary  to  make  an 
examination  of  a  cadaver,  a  splenic  'puncture  is  made,  and  the 
fluid  obtained  by  this  puncture  is  examined. 

Bacillus  subtilis  and  the  bacillus  of  malignant  oedema  may 
be  mistaken  for  the  anthrax  bacillus.  The  former  is  motile 
and  a  strict  aerobe  and  non-pathogenic,  whereas  the  latter  is 
a  strict  anaerobe,  motile,  and  is  decolorized  by  Gram's  stain. 
It  also  ditfers  from  the  anthrax  bacillus  in  its  pathogenesis. 

Bacillus  Anthracoides. 

An  organism  has  been  described  which  resembles  the  an- 
thrax bacillus  so  closely  as  to  be  mistaken  for  it  at  times. 
This  organism  is  called  Bacillus  anthracoides.  It  is  short  and 
thick,  but  not  nearly  so  long  as  Bacillus  anthracis.  Neither 
does  it  form  such  long  chains.  It  is  encapsulated  and  forms 
spores  which  are  stained  with  difficulty.  It  is  motile,  stains 
easily  with  the  anilin  dyes  and  by  Gram's  methoJ" 

Bacillus  of  Symptomatic  Anthrax. 

Symptomatic  anthrax,  also  known  as  "  quarter- evil "  or 
"  black  leg,''  is  a  disease  of  cattle. 

It  is  due  to  Bacillus  anthracis  symptomatici,  an  organism 
which  also  resembles  the  anthrax  bacillus. 

Morphology  and  biology:  The  bacillus  measures  from  3  fi 
to  5  fi  in  length,  and  from  0.5  //  to  0.6  /jl  in  width  ;  it  is  much 
smaller  than  the  anthrax  germ,  has  rounded  ends,  and  usually 
is  seen  singly  or  in  pairsj.  It  never  forms  long  chains.  It 
is  actively  motile,  and  has  both  lateral  and  terminal  flagella. 
It  forms  spof5S7^v^hich  are  large  and  centrally  located,  impart- 
ing to  the  organism  a  Clostridium  shape  (Fig.  136). 

The  anilin  dyes  stain  it  very  readily,  but  it  is  decolprizfid. 
by  Grain's  stain.     It  is  a  strict  anaerobe,  with  a  temperature 

20— Bact. 


306 


ANTHRAX:  AND  HYDROPHOBIA. 


optimum  near  that  of  the  body.     The  spores  are  quite  resis- 
tant to  heat,  desiccation,  and  chemicals. 

The  growth  on  culture-medium  develops  as  many  small 
white  colonies.  In  gelatin  a  stocking-shaped  liquefaction  like 
that  formed  by  the  Finkler-Prior  bacillus  occurs  (Fig.  137). 
All  the  cultures  give  off  a  peculiar  odor.  Much  gas  is  formed. 


Bacillus  of  symptomatic  anthrax,  containing  spores,  from  an  agar-agar-culture. 
X  1000.    (Fraenkel  and  Pfeiffer.) 

In  bouillon  the  culture  sinks  to  the  bottom.  Milk  remains 
unchanged. 

Pathogenesis :  The  organism  is  pathogenic  for  cattle  and 
sheep  only.  No  cases  of  infection  in  man  have  been  noted. 
The  infection  in  animals  usually  occurs  through  a  deep  wound 
of  the  skin,  through  which  the  bacillus  gains  entrance  to 
the  subcutaneous  tissues.  The  organism  is  also  found  in  the 
soil,  and  it  is  possible  that  it  is  ingested  by  the  animal  while 
feeding. 

One  attack  of  the  disease  confers  absolute  immunity.  Arti- 
ficial immunity  can   be  ])roduced  in  small  animals,  like  mice 


HYDROPHOBIA. 


307 


and   rabbits,  by  intravenous   inoculation ;  or  the  inoculation 
may  be  made  in  a  little  pocket  at  the  root  of  the  tail.     For 
the  production  of  immunity   in   cattle,  a  dry  powder  made 
from  the  muscles  of  animals  dead  with  the 
disease  has  been  used  with  much  success. 


fi-,^» 


Hydrophobia  (Rabies;  Lyssa). 

Although  the  specific  cause  of  rabies  is  as 
yet  unknown,  its  clinical  history  corresponds 
with  the  history  of  the  other  infectious  dis- 
eases so  closely  that  no  other  inference  is  pos- 
sible than  that  the  disease  is  caused  by  some 
micro-organism.  The  exciting  cause,  then,  is 
unknown.  All  we  know  of  this  disease  and 
of  its  action  and  manifestations  and  results 
we  owe  to  the  painstaking  and  untiring  work 
of  the  great  Pasteur.  Even  the  treatment 
which  is  of  the  most  avail  originated  with 
him. 

All  warm-blooded  animals  are  susceptible 
to  rabies.  It  is  communicated  to  man  by 
direct  inoculation. 

Judging  from  the  very  rapid  action  of  the 
infectious  material  and  the  fact  that  the  prin- 
cipal manifestations  of  the  disease  are  at  points 
far  distant  from  the  site  of  inoculation,  we  can 
come  to  only  one  conclusion — that  the  disease 
is  a  toxaemia.  It  can  be  classed  with  tetanus 
and  diphtheria. 

The  most  common  source  of  infection  is  a 
rabid  animal,  especially  the  dog,  which  by  its 
bite  conveys  the  disease  to  man. 

Hydrophobia  is  a  common  disease  in  most 
countries  of  Europe,  especially  France,  Russia,  and  Belgium. 
It  is  rather  infrequent  in  this  country  ;  in  Australia  the  disease 
is  entirely  unknown. 

In  order  that  infection  can  take  place,  it  is  necessary  that 
there  be  an  injury,  and  that  the  saliva  of  the  affected  animal 


Colonies  of  the  ba- 
cillus of  symptom- 
atic anthrax,  in 
deep  gelatin  cult- 
ure. (After  Fraenkel 
and  Pfeiffer.) 


308  ANTHRAX;   AND  HYDROPHOBIA, 

come  into  direct  contact  with  the  wound.  Whatever  the 
poison  may  be,  it  is  evidently,  elaborated  in  the  salivary 
glands,  the  parotid  gland  being  the  one  most  involved  The 
secretions  of  the  lachrymal,  adrenal,  and  mammary  glands, 
and  the  pancreas,  may  also  contain  the  virus.  The  brain 
and  spinal  cord,  especially  the  medulla  oblongata,  are  highly 
virulent.  The  virus  has  never  been  found  in  the  blood,  urine, 
or  aqueous  humor  of  the  eye. 

As  in  the  case  of  tetanus,  the  virus  of  rabies  has  a  selective 
action  on  the  nerve  tissues  in  general  and  the  central  nervous 
system  in  particular. 

The  symptoms  are  not  manifested  immediately  after  the 
injury,  but  after  a  definite  period  of  incubation,  during  which 
the  causative  germ  is  elaborating  its  toxin. 

The  period  of  incubation  and  the  severity  of  the  disease  are 
dependent  upon  several  factors.  The  usual  period  of  incu- 
bation is  from  twenty  to  sixty  days ;  but  several  cases  have 
been  reported  in  which  the  period  of  incubation  lasted  for 
several  months.  The  factors  which  influence  the  incubative 
period  are,  first,  the  character  and  location  of  the  wound ; 
second,  the  amount  of  virus  introduced  into  the  body  ;  third, 
the  virulence  of  the  poison. 

The  period  of  incubation  is  very  short  when  the  wound  is 
a  lacerated  one,  especially  of  the  face ;  or  when  it  is  located  in 
some  portion  of  the  body  that  is  well  supplied  with  nerves, 
such  as  the  finger-tips;  or  where  a  large  nerve-trunk  is  very 
near  to  the  injury,  as  at  the  elbow-joint. 

Slight  or  clean-cut  wounds  and  wounds  of  the  back  are 
usually  followed  by  long  periods  of  incubation  ;  and,  in  gen- 
eral, deep  wounds  are  followed  by  shorter  periods  of  incuba- 
tion than  are  superficial  wounds. 

These  facts  would  naturally  lead  to  the  conclusion  that  the 
germ  causing  this  disease  is  undoubtedly  an  anaerobic  organism, 
and  that  may  account  for  the  fact  that  it  has  not  as  yet 
been  discovered,  for  it  may  have  to  be  grown  in  a  certain 
atmosphere. 

Infection :  It  has  been  determined  experimentally  that  sub- 
cutaneous injection  of  the  virus  is  not  productive  of  the  dis- 
ease unless  the  virus  is  injected  deeply  into  a  muscle  or  near 


HYDROPHOBIA.  309 

a  large  nerve-trunk  or  into  a  peripheral  nerve.  Rabies  has, 
however,  followed  absorption  of  the  virus  by  an  intact  mucous 
membrane,  such  as  that  of  the  nose,  or  the  conjunctiva,  or  the 
genitalia,  or  the  digestive  tract.  Intravenous  injection  always 
is  followed  by  positive  results.  Intra-uterine  infection  is  also 
possible.  The  nervous  system  of  an  animal  dead  of  rabies 
contains  a  sufficient  quantity  of  virus  to  produce  the  disease 
when  these  tissues  are  injected  into  other  animals. 

Vitality :  The  virus  is  extremely  resistant  to  chemicals  and 
temperature.  An  exposure  of  one  hour  to  a  temperature  of 
50°  C.  is  necessary  to  destroy  the  virus.  A  5  per  cent,  solu- 
tion of  carbolic  acid  is  destructive  in  fifty  minutes.  The 
same  is  true  of  a  1 :  1000  bichloride  solution  and  a  5  per 
cent,  potassium  permanganate  solution.  The  desiccated  spinal 
cord  of  an  animal  dead  of  hydrophobia  retains  its  virulence 
for  two  weeks. 

Immunization:  The  treatment  of  rabies,  aside  from  the 
treatment  of  recent  and  single  wounds,  which  is  surgical,  is 
limited  almost  entirely  to  preventive  inoculation  with  hydro- 
phobic serum.  Pasteur  began  by  inoculating  animals  with 
preparations  of  spinal  cords  possessing  only  a  slight  degree 
of  virulence,  and  gradually  increased  the  virulence  of  the 
injection  until  he  succeeded  in  producing  immunity,  which 
protected  the  animal  against  a  quantity  of  virus  that  would 
invariably  kill  an  unprotected  animal. 

In  order  that  the  treatment  may  be  a  success,  it  is  abso- 
lutely necessary  that  the  patient  come  under  the  observation 
of  a  physician  as  soon  after  the  injury  as  possible.  Usually 
people  are  inclined  to  temporize  and  see  whether  or  not  any- 
thing will  happen  to  the  victim.  After  the  symptoms  of  the 
disease  have  appeared  it  is  too  late. 

The  serum  which  is  used  for  "  curative  "  purposes  consists 
of  an  emulsion  of  the  rabbit's  spinal  cord  which  has  been 
dried  over  caustic  potash  for  from  seven  to  ten  days.  The 
first  injection,  which  is  made  subcutaneously,  consists  of 
about  two  grams  of  this  emulsion.  This  dose  is  repeated 
every  day  for  twenty-five  days.  For  each  successive  injec- 
tion an  emulsion  is  used  which  is  made  from  a  cord  which 
has  not  been  dried  so  long,  and  which  contains  a  more  viru- 


310  ANTHRAX;  AND  HYDROPHOBIA. 

lent  virus.  The  last  injection  consists  of  an  emulsion  made 
from  a  spinal  cord  which  was  dried  for  only  three  days.  The 
treatment  is  really  a  process  of  immunization  carried  out 
during  the  period  of  incubation. 

The  emulsion  is  made  by  rubbing  up  1  centimeter  of  dried 
spinal  cord  with  four  or  five  times  its  bulk  of  bouillon  until  a 
perfect  emulsion  results.  The  injection  is  made  with  a 
syringe  sufficiently  large  to  contain  the  required  amount  of 
the  serum.  No  two  injections  should  be  made  in  the  same 
place.  Needless  to  say  that  everything  should  first  be  rendered 
sterile  in  order  to  prevent  the  occurrence  of  sepsis.  The 
injections  are  usually  made  into  the  hypochondriac  region. 

A  number  of  methods  of  immunization  against  rabies  have 
been  proposed  by  different  clinicians,  but  the  results  obtained 
by  Pasteur's  method  have  thus  far  not  been  surpassed.  Dur- 
ing the  year  1897,  1521  cases  were  immunized  at  the  Pasteur 
Institute  in  Paris  in  the  manner  described,  and  only  one  of 
these  died.  In  all  the  other  years  that  the  emulsion  has 
been  used  the  results  have  been  equally  good,  and  ought  to 
convince  the  most  skeptical  that  this  is  the  only  method  of 
treatment  of  rabies  which  is  productive  of  favorable  results. 


CHAPTER  XV. 

BACILLUS  OF  MALIGNANT  (EDEMA ;   BACILLUS  AEROG- 
ENES  CAPSULATUS;  BACILLUS  PROTEUS  VULGARIS, 

The  bacillus  of  malignant  oedema   is   identical   with   the 
Vibrion  septique  of  Pasteur.     It  is  a  large  slender  bacillus, 


Fig.  138. 


Bacillus  of  malignant  oedema,  from  the  body-juice  of  a  guinea-pig  inoculated  with 
garden  earth.     X  1000.    (Fraenkel  and  Pfeiffer.) 

with  rounded  ends.  It  possesses  both  terminal  and  lateral 
flagella,  and  is  actively  motile.  It  is  usually  found  in  pa,ij;s, 
but  in  culture  it  forms  long  chains  and  filaments  (Fig.  138). 
It  is  very  difficult  to  cultivate  the  germ.  When  grown  at 
the  temperature  of  the  body,  it  forms  a  large  oval  spore 
which  is  situated  either  in  the  middle  or  at  one  end  of  the 

311 


312 


BACILLUS  OF  MALIGNANT  (EDEMA. 


Fig.  139. 


germ.     It  is  decolorized  by  the  Gram  method,  but  stains  well 

with  the  anilin  dyes. 

The  bacillus  of  malignant  oedema  is  easily  obtained  from 
the  (Edematous  tissues  of  animals  suffering 
with  the  disease,  or  from  contaminated  gar- 
den earth.  The  bacillus  of  tetanus  is  fre- 
quently associated  with  it.  It  is  an  obliga- 
tive  anaerobe. 

The  colonies  usually  develop  in  the  depth 
of  the  medium,  and  are  solid-looking  masses, 
white  in  color.  The  colonies  have  a  very 
irregular  edge  like  those  of  the  hay  or  potato 
bacilli,  and  appear  to  be  filled  with  a  mass  of 
threads  (Fig.  139).  6re/a^i/i  is  liquefied.  In 
glucose-gelatin  gas\Q  evolved,  and  there  is  a 
distinct  odor.  Blood-serum  is  usually  rapidly 
liquefied.  Bouillon  is  rendered  turbid,  with 
the  formation  of  COg  and  hydrogen. 

The  organism  is  invariably  present  in  2^^- 
trefactivep}'ocesses,  in  garden  earth,  in  manure, 
and  in  dust,  and  is  always  associated  with  the 
tetanus  bacillus  and  several  saprophytic  germs. 
Only  a  very  few  cases  of  malignant  cedema 
have  been  reported  as  occurring  in  man.  As 
in  the  case  of  the  tetanus  bacillus,  a  penetrat- 
ing wound  is  necessary  before  infection  will 
occur.  In  fact,  the  same  conditions  which 
obtain  in  infection  with  the  tetanus  bacillus 
also  hold  good  in  infection  with  the  bacillus 
of  malignant  oedema.  Animals  are  readily 
immunized  to  infection. 

Bacillus  aerogenes  capsulatus  :  This  organ- 
ism was  discovered  by  ^^elch  in  the  blood- 
vessels of  a  patient  suflPering  with  an  aortic 
aneurism.  It  is  a  straight  or  slightly  curved 
rod,  of  variable  length  and  thickness,  with 

either  rounded  or  squared  ends.     It  is  encapsulated  and  forms 

long  chains  of  filaments.     It  is  non-motile  and  does  not  form 

S£ores. 


Colonies  of  the  ba- 
cillus of  malignant 
CEdema  in  deep  gel- 
atin culture.  (After 
Fraenkel  and  Pfeif- 
fer.) 


BACILLUS  A^BOGENES  CAPSULATUS. 


313 


The  Bacillus  aerogenes  capsulatus  is  an  obligative  anaerobe, 
and  grows  best  at  the  temperature  of  the  body.  It  stains 
well  with  the  anilin  dyes,  and  also  by  Gram's  method. 

Nutrient  gelatin  is  peptonized  but  not  liquefied.  In  agar- 
agar  gray'ish-wh'ite  irregular  round  colonies  are  formed,  which 
have  fine,  hair-like  projections.  Milk  is  coagulated  and 
litmus-milk  is  decolorized.  All  the  cultures  are  accompanied 
by  abundant  evolution  of  gas. 

The  bacillus  is  not  very  resistant  to  heat  or  to  chemicals. 
A  ten  minutes'  exposure  to  a  temperature  of  58°  C.  is  fatal. 

Fig.  140. 


Proteus  vulgaris.    X  285,    (Hauser.) 


The  organism  is  found  in  the  soil  and  the  intestines,  and  occa- 
sionally upon  the  skin. 

Pathogenesis :  The  organism  is  not  pathogenic,  but  when 
associated  with  other  germs  it  may  be  the  cause  of  death. 
It  finds  a  ready  lodgement  in  old  blood-clots,  especially  in 
aneurisms.  After  death,  when  the  blood  is  no  longer  oxy- 
genated, the  germ  grows  very  rapidly  in  the  tissues  with  an 
enormous  production  of  gas. 

In  man  infection  follows  an  injury,  especially  when  dirt  has 
been   ground  into  the   wound.     The  gas   produced   by   the 


314  BACILLUS  PROTEUS   VULGARIS. 

organism  is  inflammable.  At  the  autopsy  gas  bubbles  are 
found  in  most  of  the  internal  organs ;  and  also  the  bacillus  in 
pure  culture. 

Bacillus  proteus  vulgaris :  The  proteus  bacilli  are  minute 
rods,  usually  arranged  in  pairs  and  occasionally  forming 
chains  or  filaments.  They  possess  many  flagella  and  are 
exceedingly  motile.  The  organisms  can  be  stained  with 
carbol-fuchsin,  but  not  with  the  anilin  dyes  nor  by  Gram's 
method ;  they  do  not  form  spores ;  and  grow  equally  well  at 
either  the  room  or  body  temperature. 

Oi\  gelatin  plates  ^TU'diW  yellowish  round  colonies  are  formed, 
which  have  an  irregular  margin  and  many  fine,  hair-like  pro- 
jections (Fig.  140).  The  gelatin  is  rapidly  liquefied,  with 
the  formation  of  free  islands  of  the  growth.  This  peculiar 
appearance  of  the  culture  has  given  to  this  organism  the 
name  Bacillus  figurans.  The  growth  on  either  potato,  agar, 
bouillon,  or  gelatin  is  not  characteristic.  All  the  cultures 
give  oif  an  extremely  disagreeable  odor. 

The  proteus  bacilli  are  present  in  all  putrefactive  processes^ 
and  especially  when  these  are  situated  in  the  gastro-intestinal 
canal.  Febrile  icterus,  or  WeiFs  disease,  is  said  to  be  caused 
by  a  proteus  infection. 

Plates  are  made  from  the  pus  obtained  from  putrid  phleg- 
mons, and  also  from  the  urine  obtained  from  cases  of  Weil's 
disease. 


CHAPTER  XVI. 

MALTA  FEVER;    MUMPS;    RELAPSING  FEVER; 
WHOOPING-COUGH. 

Micrococcus  Melitensis. 

In  1887  Bruce  succeeded  in  isolating  a  micrococcus  from 
the  spleen,  liver,  and  kidneys  of  persons  suffering  from  Malta 
fever.  The  injection  of  pure  cultures  of  this  organism  into 
animals  produced  the  disease,  thus  establishing  its  specificity. 
It  also  agglutinated  with  the  serum  of  Malta  fever  patients. 

Morphology  and  biology :  Micrococcus  melitensis  measures 
about  3  /^  in  diameter  and  usually  occurs  singly.  Chains  are 
never  formed.  It  stains  well  with  an  aqueous  solution  of 
gentian-violet,  but  not  by  Gram's  method.  It  exhibits 
Brownian  movement,  but  not  actual  motility. 

The  organism  grows  well  on  agar-agar  at  the  body  tem- 
perature, forming  very  minute  round  translucent  colonies^ 
which  do  not  become  confluent.  The  growth  is  not  apparent 
until  after  forty-eight  hours.  In  the  gelatin  stab  and  agar 
stroke  the  development  is  the  same  as  on  the  plate,  but  the 
colonies  gradually  increase  in  size  until  they  finally  form  a 
rosette-like  mass.  The  track  of  the  needle  shows  a  brownish 
growth  with  serrated  edges.  If  the  tube  containing  the 
growth  is  examined  by  transmitted  light,  the  centre  of  the 
colonies  composing  the  growth  is  yellowish  in  color  and  the 
periphery  bluish-white.  By  reflected  light  the  entire  colony 
is  milky  in  appearance. 

The  growth  in  gelatin  is  always  imperceptible.  The 
medium  is  not  liquefied.     There  is  no  growth  on  potato. 

The  natural  habitat  of  this  germ  and  the  method  of  infec- 
tion are  unknown.  It  is  always  found  in  the  organs  of 
Malta  fever  cadavers,  and  can  also  be  obtained  in  pure  cult- 

315 


316  MALTA  FEVER,  ETC. 

ure   by  splenic   puncture.     It  is   pathogenic  for   the   usual 
laboratory  animals. 

Mumps — Epidemic  Parotitis. 

Pasteur  discovered  a  bacillus  in  the  blood  of  persons  suffer- 
ing from  epidemic  parotitis.  Micrococci  and  other  bacilli 
have  been  found  in  the  blood,  urine,  and  saliva.  The  diffi- 
culty which  naturally  attends  the  study  of  these  organisms, 
because  of  their  location  in  the  parotid  gland  and  their  con- 
tamination, as  they  pass  through  the  mouth,  with  both  sta- 
phylococci and  streptococci,  is  probably  one  reason  why  the 
specific  cause  of  this  disease  has  not  been  discovered. 

A  diplococcus  which  grows  in  pairs  and  fours  and  in 
zoogloea  masses  has  also  been  described. 

Pasteur  obtained  his  Bacillus  parotitis  directly  from  Sten- 
son's  duct  after  thoroughly  disinfecting  the  mouth,  and  also 
by  withdrawing  a  few  drops  of  fluid  from  the  inflamed 
parotid  gland  with  a  hypodermic  syringe. 

The  bacillus  grows  very  slowly,  which  is  characteristic, 
forming  small  white  colonies  on  gelatin.  The  medium  is 
gradually  liquefied.  On  potato  it  begins  as  a  thin  white 
streak  which  slowly  spreads  over  the  surface  of  the  potato. 
The  growth  on  hlood-serum  is  more  rapid  but  not  character- 
istic. Milh  is  coagulated ;  litmus-mWk  is  decolorized  by  the 
production  of  acid. 

This  germ  has  never  been  found  in  the  mouth  of  healthy 
persons.  Injections  of  pure  cultures  into  animals  have  not 
as  yet  produced  the  disease. 

The  diplococcus,  which  has  been  found  in  the  blood  and 
feces,  was  contained  in  the  cells  like  a  gonococcus ;  but  it  is 
considerably  smaller  than  the  gonococcus. 

This  diplococcus  stains  readily  with  the  anilin  dyes,  but 
not  by  Gram's  method. 

When  cultivated,  it  forms  very  minute  transparent  colonies 
which  remain  discrete.  On  slightly  alkaline  media  the 
growth  is  more  rapid.  Ascitic  fluid  is  also  available  as  a 
culture-medium.  Milk  is  coagulated.  It  has  not  been  pos- 
sible to  establish  its  specificity. 


RELAPSING  FEVER. 


317 


Relapsing  Fever. 

The  exciting  cause  of  relapsing  fever  is  the  spirochaete  of 
Obermeier,  or  the  spirochsete  of  relapsing  fever.  This  organ- 
ism is  seen  usually  as  a  very  long,  wavy  thread  varying  in 
length  from  16  //  to  40  /i.  It  is  flagellated  and  actively  motile 
(Figs.  141  and  142).  Sporulation  has  not  been  observed.  It 
has  not  been  cultivated  as  yet. 

The  spirochaete  is  readily  stained  with  the  aqueous  solutions 
of  the  anilin  dyes,  but  is  decolorized  by  Gram's  stain.  Guen- 
ther's  method  of  staining  is  quite  useful ;  The  fixed  cover- 

FiG.  141. 


Very  large  spirilla.    (Park.) 


glass  is  immersed  in  5  per  cent,  acetic  acid  for  ten  seconds,  in 
order  to  extract  the  haemoglobin  from  the  red  corpuscles ;  it 
is  then  stained  with  anilin  gentian-violet  or  fuchsin. 

Pathogenesis :  The  organism  is  always  found  during  the 
paroxysm  in  the  blood  of  patients  sick  with  relapsing  fever. 
It  disappears  in  the  interval.  It  has  also  been  found  in  leeches 
that  have  gorged  themselves  with  the  blood  of  such  fever 
patients. 

These  organisms  appear  in  the  blood  just  before  the  onset 
of  the  paroxysm,  during  which  they  multiply  rapidly,  and 
disappear  just  before  the  crisis.  The  spirochsete  is  strictly  a 
blood  parasite. 


318  MALTA  FEVER,  ETC. 

The  disease  is  contagious,  but  the  method  of  infection  is 
not  known.  It  is  possible  to  produce  the  disease  experi- 
mentally in  animals  by  inoculating  them  with  the  blood  of 
relapsing  fever  patients.  It  has  been  suggested  that  insects 
play  an  important  role  in  the  transmission  of  the  disease, 
but  such  a  method  of  infection  has  not  been  demonstrated. 
Intra-uterine  transmission  has  been  observed.  The  inability 
to  cultivate  this  organism  has  interfered  with  all  attempts  to 
learn  something  of  the  nature  of  the  disease ;  the  method  of 

Fig.  142. 


Spirillum  Obermeieri  in  blood  of  man.    X  1000.    (Fraenkel  and  Pfeiflfer.) 

infection  ;  whether  the  symptoms  are  due  to  the  germ  or  to  a 
toxaemia ;  finally  what  disposition  is  made  of  the  germ  when 
the  disease  has  run  its  course.  The  germ  may  be  disposed 
of  by  the  phagocytes  or  by  an  insusceptibility  of  the  blood, 
due  to  its  saturation  with  some  substance  which  is  fatal  to  the 
spirochaete. 

Whooping-cough. 

Various  observers  have  from   time  to  time  found  a  number 
of  organisms  in  the  sputum  of  children  suffering  from  whoop- 


WHOOPING-COUGH.  319 

ing-coiigh.  The  most  frequent  of  these  organisms  is  a  very 
small  bacillus  about  the  size  of  the  influenza  bacillus  (Fig. 
143).     It  also  gfows  somewhat  like  the   influenza  bacillus. 

Fig.  143. 


Whooping-cough  bacillus. 


The  data  at  our  disposal  do  not  warrant  any  positive  state- 
ments as  to  the  specificity  of  this  germ. 

Infection  in  whooping-cough  probably  always  occurs  through 
the  respiratory  tract,  the  sputum  acting  as  the  infecting 
medium.     One  attack  usually  confers  immunity. 


CHAPTER    XVII. 

ACUTE  EXANTHEMATA. 

The  specific  causes  of  the  various  exanthematous  diseases 
are  unknown.  That  these  diseases  are  due  to  bacteria  can- 
not be  doubted.  They  are  highly  contagious,  and  run  a  course 
which  corresponds  to  the  life-cycle  of  an  organism.  By 
exercising  the  usual  precautions  observed  in  all  diseases  hav- 
ing a  bacterial  cause,  the  spread  of  the  exanthemata  is  pro- 
hibited. All  cases  have  their  origin  in  some  other  case,  so 
that  the  exciting  cause  cannot  be  otherwise  than  bacterial. 
Furthermore,  one  attack  confers  an  immunity  which  under 
ordinary  conditions  is  permanent. 

Measles  :  In  measles  the  most  frequently  occurring  organ- 
ism has  been  a  coccus  obtained  fiom  the  blood  of  patients 
sick  with  measles.  Its  specificity  has  not  been  proved,  how- 
ever. The  contagium  is  contained  in  the  nasal  mucus,  the 
conjunctival  secretion,  the  sputum,  and  the  blood.  Contact 
with  the  sick  is  necessary  before  infection  can  occur.  Measles 
is  rarely  conveyed  by  clothing  or  carried  any  great  distance. 
Children  are  more  susceptible  to  the  disease  than  adults,  but 
when  adults  are  infected  the  disease  usually  runs  a  very  severe 
course.     One  attack  confers  immunity. 

Scarlet  fever :  The  virus  of  scarlet  fever  is  much  more 
virulent  than  that  of  measles. 

Infection  may  occur  even  months  after  recovery,  from 
handling  the  clothing  or  anything  else  that  the  patient  may 
have  used  during  his  illness.  Direct  contact  with  the  con- 
tagious element  is  necessary.  Infection  usually  occurs  through 
the  respiratory  tract.  The  scales  appear  to  play  a  very 
important  role  in  conveying  the  disease,  but  just  how  is  still 
a  matter  of  conjecture. 

Streptococci  and  diplococci  of  various  kinds  have  been 
found  in  the  blood  and  scales  of  scarlet  fever  patients.     The 

320 


SMALLPOX.  321 

poison  is  apparently  excreted  by  the  kidneys,  as  these  organs 
are  frequently  and  extensively  involved,  especially  in  severe 
cases. 

Class,  a  few  years  ago,  described  a  diplococcus  which  he 
believed  to  be  the  specific  cause  of  scarlet  fever.  He  named 
it  Diplococcus  scarlatlnce.  Proof  positive  as  to  its  relationship 
to  the  disease  is  wanting,  however.  Class  grew  this  germ  on 
a  mixture  of  agar-agar  and  garden  earth.  It  could  not  be 
cultivated  in  any  medium  which  did  not  contain  earth. 

One  attack  of  scarlet  fever  confers  immunity,  although 
second  attacks  have  been  recorded.  Scarlatina,  like  measles, 
is  a  disease  of  youth,  and  when  it  occurs  in  adults  it  is  as  an 
aggravated  form  of  the  disease. 

Smallpox:  The  exciting  cause  of  smallpox  is  also  unknown. 
The  virus  is  known  to  be  contained  in  the  pustules,  in  the 
desquamating  skin,  in  the  sputum,  and  in  the  nasal  secretions 
of  smallpox  patients.  The  virus  retains  its  virulence  for 
many  months. 

Infection  is  conveyed  through  the  air  and  by  bed-clothing, 
linen,  and  other  articles  that  may  have  been  contaminated 
by  the  virus ;  but  tlie  nature  of  the  infection  and  the  method 
of  conveyance  have  not  been  determined.  The  skin  and  the 
respiratory  tract  would  naturally  suggest  themselves  as  portals 
of  infection,  and  yet  the  first  symptoms  of  smallpox,  as  in 
measles  and  scarlatina,  are  not  local  but  general  manifesta- 
tions indicative  of  an  intoxication.  One  case  of  smallpox, 
unless  isolated,  may  form  the  nidus  of  a  practically  unlimited 
epidemic.  The  same  is  true  of  scarlet  fever.  Isolation  and 
protection  of  the  well  effectually  check  the  spread  of  the  dis- 
ease. It  is  possible  that  the  virus  may  be  inhaled,  but,  with 
rare  exceptions,  smallpox  lesions  do  not  develop  in  the  respi- 
ratory tract.  The  skin  is  the  usual  seat  of  the  exanthematous 
eruption,  and  perhaps  the  infection  enters  by  that  channel. 
Microscopic  examination  has  shown  that  the  tissue-cells  in 
the  infected  areas  contain  from  one  to  four  spheroidal  or 
slightly  irregular  bodies  which  vary  in  size,  the  largest  being 
of  the  size  of  a  cell-nucleus.  With  nuclear  stains  they  stain 
more  faintly  than  the  nucleus.  They  are  homogeneous. 
When   the  hsematoxylin  and  eosin  double  stain  is  used,  the 

21— Bact. 


322  ACUTE  EXANTHEMATA. 

nucleus  of  the  cell  is  stained  a  dark  purple,  the  cell-bodies 
pink,  and  the  peculiar  bodies  a  light  uniform  purple. 

Immunity :  One  attack  of  smallpox  confers  an  immunity 
of  from  ten  to  twenty  years'  duration,  although  not  infre- 
quently the  immunity  persists  for  a  lifetime.  A  mild  attack 
of  the  disease  will  confer  immunity  against  severe  attacks. 
This  fact  forms  the  basis  of  vaccination,  which  is  now  prac- 
tised almost  universally. 

The  virus  used  for  vaccination,  or  vaccine,  is  obtained  from 
the  pustules  of  cowpox.  The  contents  of  the  pock  are  rubbed 
up  with  glycerin.  Human  lymph  was  also  used  at  one  time, 
but  its  use  has  been  abandoned  for  the  bovine  lymph,  because 
of  the  possibility  of  its  being  contaminated  with  tuberculosis 
and  syphilis.  The  bovine  vaccine  is  also  more  easily  obtained. 
The  vaccine  is  placed  on  the  market  either  in  the  form  of 
an  ivory  point  which  is  coated  on  both  sides  with  the  dried 
vaccine  ;  or  in  capillary  tubes.  Good  vaccine  will  keep  in 
sterilized  capillary  tubes  for  three  months,  although  some 
tubes  deteriorate  before  that  time. 

Vaccine  always  contains  bacteria^  very  few  of  which  are 
pathogenic,  however.  These  organisms  usually  disappear 
from  the  lymph  within  three  or  four  months.  For  this 
reason  it  is  not  well  to  use  too  fresh  a  lymph,  because  it  may 
contain  staphylococci,  which  will  induce  severe  local  suppu- 
ration around  the  vaccinated  area,  or  even  a  fatal  pyaemia. 

Recent  investigations  by  Funck  show  that  vaccinia  is 
caused  by  Sporidium  vaccinale,  a  parasitic  protozoon.  Animals 
inoculated  wnth  this  organism  developed  both  vaccinia  and 
variola.  These  organisms  were  found  in  the  lymph,  in  the 
smallpox  vesicle,  and  also  in  sterile  glycerinated  vaccine. 

When  examined  in  the  hanging  drop  two  forms  of  this 
organism  are  seen.  One,  a  cyst-form  filled  with  spores,  and, 
second,  free  spores.  The  spore-cysts  are  round  or  oval,  and 
about  25 /i  in  diameter.  The  spores  are  irregular  in  outline, 
highly  refractive  and  motile,  measuring  from  1  to  3  /i  in 
diameter.  Larger  bodies,  which  look  like  epithelial  cells  filled 
with  the  organism,  are  also  seen  occasionally. 

Sporidium  vaccinale  can  be  obtained  in  pure  culture  by 
plating  in  agar  a  few  drops  of  sterile  glycerinated.  vaccine. 


SMALLPOX.  323 

These  findings  have  been  confirmed,  but  the  bacterial  origin 
of  vaccine  and  smallpox  is  doubted  by  many  investiga- 
tors. 

Vaccination :  It  is  advisable  to  vaccinate  at  least  once  in 
every  seven  years,  aud  oftener  in  case  of  an  epidemic  of 
smallpox.  Unless  smallpox  is  epidemic,  it  is  not  necessary 
to  vaccinate  an  infant  at  the  time  of  its  birth.  Neither  is  it 
desirable  to  vaccinate  babies  during  the  first  or  even  second 
summer  of  their  existence.  On  the  whole,  it  is  better  not  to 
vaccinate  the  infant  until  it  has  passed  through  the  periods 
of  stress  which  it  must  encounter  during  its  first  years  of 
life.  In  case  of  a  smallpox  epidemic,  however,  the  child 
should  be  vaccinated  immediately. 

The  usual  site  for  vaccination  in  boys  is  the  skin  over  the 
insertion  of  the  deltoid  muscle  of  the  left  arm.  In  girls,  for 
aesthetic  reasons,  the  skin  on  the  back  of  the  calf,  or  on  the 
inner  side  of  the  thigh  near  the  knee,  is  chosen.  Other 
portions  of  the  body  may  be  selected.  Some  one  has  pro- 
posed to  vaccinate  over  the  epigastrium,  because  that  part  of 
the  body  is  more  easily  protected  from  injury. 

In  performing  a  vaccination,  we  should  keep  in  mind  that 
it  is  a  surgical  operation,  and  that  the  strictest  antiseptic  pre- 
cautions should  be  observed.  Everything — the  site  of  vac- 
cination, the  hands  of  the  operator,  and  the  instrument  used 
— should  be  thoroughly  cleansed  and  disinfected.  Unfortu- 
nately, vaccination  is  too  often  looked  upon  as  a  trivial  pro- 
cedure. It  is  done  in  a  hurry,  and  without  regard  for  either 
asepsis  or  antisepsis.  Most,  if  not  all,  of  the  disastrous 
results  which  follow  vaccination  can  be  ascribed  to  improper 
methods  and  carelessness.  It  is  customary  to  blame  the  vac- 
cine, but  more  often  it  is  the  fault  of  the  vaccinator. 

After  everything  is  ready  the  shin  is  scarified.  This  scari- 
fication may  be  done  with  the  vaccine  point  (a  barbarous 
method) ;  a  sterilized  needle  ;  or  a  special  scarifier ;  but  the 
best  results  are  obtained  with  a  sharp  scalpel. 

The  scalpel  can  be  sterilized  or  disinfected  each  time  it  is 
used,  and  it  does  not  cause  so  much  pain  as  either  the  needle 
or  the  other  scarifiers.  The  vaccination  can  be  done  more 
accurately,  because  the  pressure  on  the  scalpel  can  be  regu- 


324  ACUTE  EXANTHEMATA. 

lated  by  the  vaccinator.  The  sharp  edge  of  the  scalpel  is 
passed  gently  to  and  fro  over  the  skin  until  the  tops  of  the 
papilla  in  the  skin  begin  to  appear.  The  scarification  is  cov- 
ered with  the  oozing  serum,  but  no  blood  is  drawn.  The 
method  is  absolutely  painless — in  fact,  it  is  accompanied  by  a 
rather  pleasant  sensation.  It  is  not  necessary  to  make  a  deep 
gash  or  a  number  of  scratches  that  draw  blood,  because  those 
vaccinations  usually  do  not  take.  No  blood  should  ever  be 
drawn,  as  it  hinders  absorption  of  the  lymph,  L  e.,  vaccine. 
The  flow  of  blood  does  not  permit  of  entrance  of  the  lymph, 
and  when  the  blood  coagulates  it  forms  an  effectual  barrier  to 
the  entrance  of  the  lymph  into  the  lymph-channels. 

The  scarification,  when  properly  performed^  is  then  covered 
with  a  very  thin  layer  of  serum,  and  into  this  the  ivory  point 
is  gently  rubbed,  after  having  first  been  dipped  into  warm 
water,  until  all  the  lymph  on  the  point  is  rubbed  off. 

If  the  capillary  tube  is  used,  the  ends  are  broken  and  the 
contents  of  the  tube  blown  on  the  scarified  area  and  rubbed 
in  with  the  scalpel ;  or  even  this  is  not  necessary,  as  the  glyc- 
erinized  lymph  is  rapidly  absorbed.  The  serum  remains  on 
the  wound  for  a  long  time  afterward,  even  after  all  the  lymph 
has  been  taken  up  by  the  lymph-vessels :  so  that  when  the 
moisture  persists  the  scarification  can  be  covered  with  a  piece 
of  sterile  absorbent  cotton ;  or  a  vaccination  shield  can  be 
applied,  and  over  this  a  dressing.  The  wound  should  be 
protected  from  infection,  and  for  this  reason  it  is  well  to  keep 
a  protective  dressing  on  until  it  has  healed. 

It  is  not  necessary  to  scarify  a  large  area,  because  a  vacci- 
nation will  take  just  as  well  in  a  small  spot  as  in  one  the  size 
of  a  silver  dollar.  It  is  not  necessary  to  have  the  "taking" 
of  the  vaccination  accompanied  by  terrific  suffering  because 
of  a  large  abraded  surface.  A  scarification  about  one-quarter 
of  an  inch  square  suffices. 

In  from  one  to  three  days  a  small  red  papule  appears. 
This  is  followed  by  a  vesicle,  and  this  by  a  pustule  which  is 
surrounded  by  a  bright-red  areola.  All  the  stages  of  a  typi- 
cal variolous  eruption  are  represented  in  this  vaccination  area. 
Ordinarily  only  slight  constitutional  symptoms  follow  a  vac- 
cination,  but  occasionally  there  may  be  high  temperature, 


SMALLPOX.  325 

chills,  headache,  malaise,  and  all  the  symptoms  of  a  mild 
attack  of  variola.  If  the  fever  is  very  high  and  the  axillary 
lymph-glands  much  enlarged  and  tender,  it  means  that  infec- 
tion with  the  pus  germs  has  occurred.  Very  sore  and  inflamed 
arms  are  not  a  part  of  a  typical  vaccination. 


PART  IV. 


MICRO-ORGANISMS  PATHOGENIC  FOR   ANIMALS  ONLY. 

Chicken  Cholera  (Bacillus  Gallinarum). 

Bacillus  gallinarum,  the  specific  cause  of  chicken  cholera,  is 
a  very  short  and  thick  bacillus,  with  rounded  ends,  occur- 
ring singly  and  in  short  chains  (Fig.  144).     Polar  staining  is 


Fig.  144. 


Bacillus  of  chicken  cholera,  from  the  heart's  blood  of  a  pigeon. 
(Fraenkel  and  Pfeiffer.) 


X  1000. 


very  marked,  giving  the  organism  the  appearance  of  a  diplo- 
coccus.  It  does  not  form  spores,  neither  is  it  motile.  Gram\s 
stain  is  not  applicable.  Heat  and  drying  are  rapidly  fatal. 
It  is  strongly  aerobic. 

All  the  cultures  of  this  germ  are  absolutely  devoid  of  any 
characteristic.     The  culture  is  white  in  color,  and   develops 

327 


328  MICRO-ORGANISMS  PATHOGENIC  FOR  ANIMALS  ONLY, 

rapidly  and  luxuriantly  at  the  incubator  temperature  on  all 
the  ordinary  media  except  potato,  on  which  the  growth  is 
almost  invisible. 

The  bacillus  is  pathogenic  for  chickens,  geese,  mice,  pigeons, 
rabbits,  etc.  The  injection  of  pure  cultures  produces  a  fatal 
septicaemia  with  pronounced  intestinal  symptoms.  The  bacil- 
lus is  found  in  all  the  organs  of  the  affected  animal,  but 
chiefly  in  the  intestine.  Chickens  inoculated  with  attenuated 
cultures  are  made  immune  to  infection  with  virulent  organ- 
isms. One  peculiarity  of  this  organism  is  that  when  injected 
into  different  species  of  animals  different  diseases  are  pro- 
duced in  each  species,  such  as  rabbit  septicaemia,  swine 
plague,  eto. 

Bacillus  Suipestifer  (Hog  Cholera). 

This  organism  belongs  to  the  same  group  as  the  colon  bacil- 
lus. It  is  the  specific  cause  of  hog  cholera,  a  disease  which 
is  both  common  and  fatal.  It  is  a  short,  thick  rod,  with 
rounded  ends,  flagellated  and  exceedingly  motile.  It  does 
not  form  spores.  It  is  stained  by  the  anilin  dyes,  but  not 
by  Gram. 

The  organism  is  easily  cultivated  on  all  the  ordinary  cult- 
ure-media at  the  temperature  of  the  body.  The  cultures  as 
well  as  the  germ  bear  some  resemblance  to  Bacillus  typhosus, 
but  the  bacillus  of  hog  cholera  produces  both  gases  and  acids. 
It  is  exceedingly  resistant  to  both  heat  and  chemicals. 

The  organism  is  markedly  pathogenic  for  animals ;  and  is 
found  in  the  intestine  of  animals  so  diseased. 

The  injection  of  gradually  increasing  doses  of  pure  cultures 
of  Bacillus  suipestifer  into  cows  immunizes  them  and  causes 
the  formation  of  an  antitoxin  in  the  blood  of  the  cow  which 
is  capable  of  protecting  guinea-pigs  from  the  disease. 

Bacillus  Suisepticus  (Swine  Plague). 

This  organism  resembles  the  bacillus  of  hog  cholera ;  and 
the  two  diseases  are  not  infrequently  associated.  The  one 
may  be  mistaken  for  the  other.  The  disease  is  rapidly  fatal. 
Bacillus  suisepticus  is  an  exceedingly  short,  thick  rod,  which 


BACILLUS  MURISEPTICUS.  329 

may  be  taken  for  a  diplococcus.  It  is  not  motile,  has  no 
flagella,  and  does  not  form  spores.  It  stains  well  with  the 
usual  dyes,  and  sometimes  exhibits  slight  polar  staining. 
Gram's  stain  is  not  applicable.  It  is  feebly  resistant  to  heat 
and  desiccation.     It  is  a  facultative  anaerobe. 

Its  growth  in  culture -media  resembles  the  cultures  of  the 
hog-cholera  bacillus.  No  growth  forms  on  potato  unless  it  is 
alkaline,  when  a  very  thin  grayish  film  is  seen  to  develop.  It 
produces  a  very  slight  amount  of  acid,  not  sufficient  to  coagu- 
late milk  nor  to  discolor  litmus  solution. 

It  is  pathogenic  for  animals  only. 

Bacillus  Typhi  Murium. 

This  is  a  very  small,  short  germ,  which  in  culture  often 
forms  very  long  filaments.  It  varies  greatly  in  thickness. 
It  is  not  motile,  although  it  possesses  numerous  flagella.  It 
does  not  form  spores;  stains  well  with  Loeffler's  alkaline 
methylene-blue  ;  it  is  a  facultative  anaerobe. 

Plate  colonies  on  gelatin  are  at  first  grayish,  but  soon  turn  a 
yellowish-brown.  In  the  gelatin  stab  a  grayish-white  growth 
is  formed  on  the  surface  of  the  medium,  with  an  almost  imper- 
ceptible growth  along  the  track  of  the  needle.  When  grown 
in  milkj  acid  is  produced,  but  the  milk  is  not  coagulated. 

The  germ  is  intensely  pathogenic  for  mice.  It  can  be  iso- 
lated from  the  blood  and  lymph-channels.  It  has  been  used 
with  remarkable  success  in  freeing  infested  houses  from 
mice  by  saturating  bread  with  a  bouillon  culture  of  .the 
bacillus.  The  bread  is  pushed  into  the  mouse-holes  at  a  time 
of  the  year  when  food  is  not  plentiful.  The  mice  which  are 
infected  in  this  way  die  rapidly,  and  their  dead  bodies  are 
eaten  by  other  mice,  which  also  succumb  to  the  disease.  In 
this  way  the  premises  can  be  rid  of  the  pests  in  a  very  short 
time,  usually  in  about  ten  or  twelve  days. 

Bacillus  Murisepticus  (Mouse  Septicaemia). 

Bacillus  murisepticus  resembles  an  organism  found  in  the 
lesions  of  swine  erysipelas  so  closely  that  these  two  germs  are 
considered  by  many  as  identical.    They  are  very  small,  about 


330  MICRO-ORGANISMS  PATHOGENIC  FOR  ANIMALS  ONLY. 


1  /J.  long  and  0.2  jj.  wide.  Flagellation,  motility,  and  sporula- 
tion  are  doubtful.  The  bacillus  is  strongly  inclined  to  be  a 
strict  anaerobe.     It  can  be  cultivated  at  either  the  body  or 

Fig.  145. 


FiQ.  146. 


Colony  of  the  bacillus  of  mouse  septicaemia.    X  80.    (Fluegge.) 

room  temperature.     It  stains  with  Gram  and  the  usual  anilin 

dyes.  It  is  killed  by  a  temperature  of  62°  C.  in  fifteen  minutes. 
The  colonies  on  gelatin  plates  resemble  the  lacunae  in  bone 
with  their  contents  and  processes  (Fig.  145). 
The  colony  is  grayish  in  color,  irregular,  and 
has  many  fine,  wavy,  branched  projections. 
The  gelatin  is  gradually  softened  and  evapo- 
rated, the  colonies  coalescing  to  form  a  gray- 
ish film. 

In  gelatin  stabs  development  takes  place 
along  the  entire  needle-track,  with  little  or 
no  surface  growth.  Usually  the  top  of  the 
growth  is  slightly  beneath  the  surface  of  the 
medium.  The  growth  in  the  gelatin  tube  is 
peculiar.  It  resembles  a  column  of  discs, 
each  disc  being  separated  from  the  other  by 
a  layer  of  cloudy  fluid  (Fig.  146).  The  gel- 
atin is  not  liquefied.  The  germ  does  not  grow 
on  potato.  On  agar-agar  or  blood-serum  the 
growth  is  devoid  of  any  characteristic. 

The  organism  is  pathogenic  for  mice  and 
swine.  The  bacilli  are  found  in  all  the 
organs,    especially    the    spleen    and    lungs. 

Many   of    the   germs   are   enclosed    by   the   leucocytes. 
It  is  possible  to  produce  temporary  immunity  by  injecting 

the  blood-serum  of  rabbits  immunized  with  pure  cultures  of 

the  bacillus. 


Bacillus  of  mouse 
septicaemia ;  gelatin 
puncture  ;  culture 
three  and  a  half 
days  old.  (Guen- 
ther.) 


APPENDIX. 


Student's  Individual  Bacteriology  Outfit. 

J  gross  slides. 

J  ounce  cover-glasses. 

1  slide  box. 

1  pointed  forceps. 

1  Stewart  forceps. 

1  inoculating  needle. 

6  dozen  test-tubes,  6  X  f  inch. 

2  dozen  test-tubes,  5X1  inch  (for  potato). 
6  Petri  dishes. 

1  1000  c.c.  flask. 
1  glass  stirring  rod. 
1  large  glass  funnel  (ribbed). 
1  large  bowl. 
1  Bunsen  burner. 
1  iron  tripod. 

1  piece  of  wire  gauze,  6X6  inches. 
1  wooden  filtering-stand. 
1  cork-borer,  f  inch. 
1  wire  test-tube  basket,  5X10  inches. 
1  test-tube  rack — 24  tubes. 
1  potato  knife. 
1  test-tube  brush. 
Cotton  batting. 
Towel  and  cheese-cloth. 
1  pint  of  alcohol  in  glass-stoppered  bottle. 
1  pint  of  sterilized  water  in  glass-stoppered  bottle. 
1  ounce  of  carbol-fuchsin  in  dropping-bottle. 
1  ounce  of  Loeffler's  alkaline  raethylene-blue  in  dropping- 
bottle. 

331 


332  APPENDIX. 

1  ounce  of  anilin  gentian- violet  in  dropping-bottle. 

1  ounce  of  Gram's  solution  in  dropping-bottle. 

1  ounce  of  30  per  cent,  nitric  acid. 

1  ounce  of  xylol  balsam. 

1  dozen  of  13-inch  filter-paper. 

1  package  of  blue  litmus-paper. 

1  slide  with  concave  centre. 

3  medicine-droppers. 

1  package  of  labels  (fifty). 

1  tube  of  vaselin. 

Syllabus  of  Laboratory  Work  in  Bacteriology. 

Explanation:  The  experiments  presented  in  this  syllabus 
cover  the  entire  requirements  of  the  first  three  months'  lab- 
oratory work  in  bacteriology.  Each  student  is  required  to 
conduct  each  experiment  personally,  and  will  receive  credit 
for  the  experiment  upon  presentation  of  the  completed  work. 
The  experiments  are  to  be  conducted  in  the  order  in  which 
they  are  placed ;  but  it  is  not  required  that  each  be  completely 
finished  before  the  next  is  begun.  However,  the  work  of 
Part  I.  must  be  completed  entirely  before  that  of  Part  II. 
can  be  undertaken.  The  details  of  the  experiments  and  the 
methods  will  receive  explanation  in  the  didactic  course. 
Specimens  for  study  and  material  for  making  media  will  be 
supplied  from  the  preparation-room  upon  application.  Each 
student  is  expected  to  make  up  sufficient  culture-media  from 
time  to  time  to  continue  the  various  experiments,  and  it  is 
therefore  taken  for  granted  that  members  of  the  class  will 
keep  themselves  at  all  times  supplied  with  sufficient  media. 

Part  I.  Technique. 

Experiment  1  :  Sterilization  hy  Dry  Heat :  Wash  and 
dry  one  wire  basket  full  of  test-tubes  and  all  of  the  Petri 
saucers  in  the  outfit.  Plug  the  test-tubes  with  cotton,  fit  the 
dishes  together,  and  sterilize  all  by  dry  heat  for  one  hour  at 
165°  C. 

Experiment  2  :  Culture-media :  (a)  Sterile  Potato  :  Pre- 
pare four  Petri  saucers  with  slices  of  potato ;  also  prepare 


APPENDIX.  333 

twelve  test-tubes  with  blocks  of  potato.  Sterilize  all  by 
steam  for  one  hour  at  100°  C. 

{h)  Prej)a7'ation  of  Sterile  Beef-tea :  Prepare  1000  c.c.  of 
beef-tea  culture-fluid.  Fill  one  dozen  sterile  test-tubes,  with 
one  inch  of  the  beef-tea  in  each,  and  sterilize  them  in  the 
steam  sterilizer  for  one  hour. 

Formula  for  nutrient  beef-tea  : 


Beef-extract, 

Peptone, 

Salt, 

2  grams ; 
10      " 
5      " 

Water, 

1000  c.c. 

(c)  Preparation  of  Nutrient  Gelatin:  Prepare  1000  c.c.  of 
nutrient  gelatin.  Fill  into  sterile  tubes  as  in  the  case  of  the 
beef-tea  and  sterilize  by  the  fractional  method.  Solidify  with 
tube  in  upright  position. 

Formula  for  nutrient  gelatin  : 


Beef-extract, 

2  grams; 

Peptone, 

10      " 

Salt, 

5      " 

Gelatin, 

100     " 

Water, 

1000  c.c. 

{d)  Preparation  of  Nutrient  Agar:  Prepare  1000  c.c.  of 
nutrient  agar.  Fill  into  test-tubes  as  in  the  case  of  gelatin 
and  sterilize.  Solidify  with  tube  in  the  inclined  position. 
The  formula  for  agar  is  like  that  of  gelatin,  excepting  that  10 
grams  of  agar  are  substituted  for  the  gelatin. 

Experiment  3 :  Demonstration  of  Sterility^  Infection,  and 
Contamination :  Select  three  of  the  Petri  saucers  containing 
sterile  potato.  Expose  one  of  them  to  the  air  for  five  min- 
utes, causing  it  to  be  contaminated.  Another,  infect  by  rub- 
bing the  finger  over  the  laboratory  desk  and  then  across  the 
potato.  The  third  allow  to  remain  closed,  so  that  it  will 
remain  sterile.  Label  each  dish  properly.  Notice  the  result 
in  the  next  few  days. 

Experiment  4  :  Study  of  a  Mould :  Select  a  well-developed 


334  APPENDIX. 

mould  colony  and  examine  its  structure  with  different  powers 
of  the  microscope.  Make  a  set  of  drawings  showing  the 
details  of  structure  and  the  mode  of  reproduction  in  the 
specimen  that  you  have. 

Experiment  5  :  (a)  Determine  the  motility  of  the  various 
growths  of  bacteria  on  potato  in  the  Petri  dishes. 

(b)  Make  four  permanent  slides  from  different  appearing 
growths,  stain  with  methylene-blue  and  examine  microscopi- 
cally.    Make  a  drawing  of  each,  showing  their  structure. 

Experiment  6  :  Staining  of  Spores:  Select  a  culture  of 
bacteria  in  which  spore-formation  can  be  seen,  and  double 
stain  the  spores  and  bacteria  (carbol-fuchsin  and  methyl-blue). 

Experiment?:  Colony  Culture:  (a)  Inoculate  a  tube  of 
beef-tea  with  a  portion  of  each  of  the  different  growths  on 
potato,  (b)  After  forty-eight  hours  make  a  plate  culture  on 
agar  and  an  agar  roll  culture,  inoculating  each  of  these  from 
the  beef-tea  culture  previously  made. 

Experiment  8 :  Tube  Culture :  Make  stab  and  streak 
cultures  on  gelatin,  agar,  potato,  and  bouillon  of  various  differ- 
ent appearing  colonies  in  the  plate  and  roll  cultures.  Label 
each. 

Experiment  9 :  (a)  Make  slides  of  each  bacterium  and 
compare  them  with  the  slides  previously  made  from  the 
original  growths  on  potato.  (6)  Make  drawings  and  describe 
fully  the  appearance  and  growths  of  each  bacterium  on  the 
various  media  and  in  the  colony. 

Experiment  10  :  Inoculate  an  agar  tube  with  a  drop  of 
tap-water ;  make  plate,  culture.  Cultivate  each  bacterium 
present,  make  slides,  drawings,  and  describe  fully  as  in  pre- 
vious experiments. 

Experiment  11  :  Study  of  most  common  non-pathogenic 
bacteria,  following  out  the  directions  laid  down  in  experi- 
ments as  above. 


APPENDIX. 


335 


Part  II.  Study  of  Pathogenic  Organisms. 
Form  to  be  Filled  Out  for  Each  Culture.^ 


Microscopic  Appearance  : 

1.  Species; 

2.  Arrangement; 

3.  Motility; 

4.  Spores; 

5.  Flagella; 

6.  Capsule. 

' 

Colony  on  Agar  Plate 
or  Roll 

Colony  on  Gelatin  Plate 
or  Boll. 

Growths  in  Tubes: 

1.  Bouillon; 

2.  Gelatin; 

3.  Agar; 

4.  Potato. 

Special  Cultures. 
Remarks. 

1  This  form  to  be  accompanied  by  a  drawing  of  bacterium,  plate  colony,  and 
tube  cultures. 


INDEX 


Achorion  Schoenleinii,  153 
Actinomyces,  152,  221 
cultures,  222 
diagnosis,  225 
forms,  221,  223 
infection,  224 
pathogenesis,  223 
staining,  222 
Actinomycosis  (see  Actinomyces),  221 
Aerobes,  29 
Agar-agar,  39 
glycerin,  40 
Agglutination,  111 
Agglutinin,  112 

Air,  bacteria  in  (see  Examination),  130 
Alcohol,  57 
Alexins,  116,  125 
Alexocytes,  116 
Alkaloids,  cadaveric,  98 
Anaerobes,  29,  76 
Animal  inoculation   (see  Inoculation), 

74 
Anthrax,  299-305 
bacillus  (see  B.  anthracis),  299 
external,  303 

"anthrax  oedema,"  303 
"  carbuncle,"  303 
malignant  pustule,  303,  304 
heredity,  304 
immunity,  304 
infection,  303 
general,  303,  304 
intrauterine,  304 
portal  of,  303 
skin,  303 

"anthrax  oedema,"  303 
''  carbuncle,"  303 
malignant  pustule,  303,  304 
tract,  gastro-intestinal,  303 
respiratory,  304 
internal,  304 

22— Bact. 


Anthrax,    internal,    gastro-intestinal 
infection,  303 
wool-sorters'  disease,  304 

oedema,  303 

pathogenesis,  302 

prophylaxis,  304 

symptomatic,  305 
bacillus,  305 
Antiamarylic  serum,  291 
Antibodies,  112 
Antiphthisin,  205 
Antiplaguo  serum,  294 
Antipneumococcus  serum,  184 
Antiseptic,  45,  56 
Antisera,  112,  167,  168,  184 
Antistreptococcus  serum,  168 
Ahtitoxic  serum,  126,  128,  129 
Antitoxins,  119,  122,  124-129 

administration,  126,  127 

chemical  composition,  125 

definition,  124 

of  diphtheria,  244-247 

ill  effects  of,  128 

manufacture,  126 

specific  action,  126 

tetanus,  234 

theories  as  to  nature  of,  124 
Antityphoid  serum,  282 
Appendix,  331-335 

student's  outfit,  331,  332 

syllabus  of  laboratory  work,  332 
Part  I.,  332 

II.,  335 
study  of  organisms,  335 
technique,  332-334 
Arthrospores,  21 
Ascococcus,  23 
Aseptic,  45 
Aspergillus  fumigatus,  150,  207 

glaucus,  150,  207 

niger,  150 
Autoinfection,  102 
Autointoxication,  102  ? 

337 


338 


INDEX. 


Bacilli,  23 
colon  group  of,  285 
comma,  24 
Bacillus  acidi  lactici,  145 
aerogenes  capsulatus,  312 
infection,  313 
pathogenesis,  313 
anthracis  {see  also  Anthrax),  299 
diagnosis,  304 

B.  of  malignant  oedema,  305 
B.  subtilis,  305 
immunity,  304 
infection,  303 

morphology  and  biology,  299 
pathogenesis,  302 
staining,  300 
symptomatici,  305 
immunity,  306 
pathogenesis,  306 
vitality,  302 

whore  found  in  the  body,  304 
anthracoides,  305 
of  anthrax  {see  B.  anthracis),  299 
butyricus,  145 
of  chicken  cholera,  327 
of  cholera    {see  Spirillum   cholerse 
Asiaticje),  250 
^  eoli  communis,  283 

biology  and  morphology,  283 
differentiation  from  B.  typho- 
sus, 272,  277,  278,  285,  286 
pathogenesis,  284 
cuniculicida  Havaniensis  {see  Bacil- 
lus icteroides),  289 
diphtherias    {see  also    Diphtheria), 
236 
antitoxin,  244 

biology  and  morphology,  237-241 
immunization,  243 
infection,  242 
mixed,  242 
occurrence,  237 
pathogenesis,  241 
staining,  238 
toxalbumin,  243 
toxin,  242,  243,  244 
vitality,  241 
dysenterise,  286 

immunizing  serum  of,  287 
of   Eberth  (see  Bacillus  typhosus), 

268 
of  Escherich  (see  Bacillus  coli  com- 
munis), 283 
cnteritidis,  286 


Bacillus  figurans,  314 
fluorescens  liquefaciens,  144 
of  Friedlauder   {see    Pueumobacil- 

lus),  185 
gallinarum,  327 

cultures,  327 

immunity,  328 

pathogenesis,  328 
hay,  141 

of  hog  cholera,  328 
icteroides   (see  also   Yellow  fever), 
289 

biology  and  morphology,  289 

infection,  290,  291 

mosquito    {see    Yellow    fever), 
291 

pathogenesis,  290 
influenzge,  295 

diagnosis,  298 

immunity,  298 

infection,  297 

morphology  and  biology,  295 

pathogenesis,  297 
Klebs-Loeffler    {see  Bacillus  diph- 
theria), 236 
leprae  {see  also  Leprosy),  209 

infection,  209 
nose,  209 
skin,  209 

inoculation  in  animals,  209 
of  leprosy  (see  Bacillus  leprae),  209 
of  malignant  oedema,  311,  312 
mallei,  217 

cultures,  218 

diagnosis,  220 

immunity,  220 
mallein,  220 

infection,  219,  220 

pathogenesis,  218 
farcy,  219 

buds,  219 
in  the  horse,  219 

prophylaxis,  221 

vitality,  218 
mesentericus  vulgatus,  142 
of  mouse  septicaemia,  329 

typhus,  329 
murisepticus,  329 

colonies  on  gelatin  plates,  330 

immunity,  330 

pathogenesis,  330 
mycoi'des,  143 
O,"  288 

Oppler-Boas,  146 
paracolon,  288 
paratyphoid,  287 


INDEX. 


339 


Bacillus,  paratyphoid,  agglutination, 

288 
paratyphosus,  287 
parotitis,  316 
pestis  [see  also  Plague),  292 

diagnosis,  295 
agglutination,  295 
staining,  294 

immunization,  294 

infection,  294 

morphology  and  biology,  292 

pathogenesis,  293 
for  animals,  293 

for  rat,  293 
for  man,  293,  294 

vitality,  293 
of  Pfeiffer,  295,  298 
of  plague  {see  also  Bacillus  pestis), 

292 
potato,  142 
prodigiosus,  143 
proteus  vulgaris,  314 
pseudodiphtheria,  247 
pseudoinfluenza,  298 
pseudotetanus,  235 
pseudotuberculosis,  207 
psittacosis,  288 
pyocyaneus,  169 

pathogenesis,  171 

pigments,  170 
ramosus,  143 
of  Sanarelli  {see  Bacillus  icteroides), 

of''shiga,  286 
smegmatis,  208 
subtilis,  141 
suipestifer,  328 
immunity,  328 
pathogenesis,  328 
suisepticus,  328 
resemblance  to  B.  suipestifer,  328, 
329 
of  svt^ine  plage,  328 
of  symptomatic  anthrax,  305 
of  syphilis  {see  also  Syphilis),  212 
diplococcus,  white,  214 
infection,  214 
Lustgarten's,  212 

preparations,  212 
Van  Niesen's,  213 

inoculation  in  animals,  214 
tetani,  228 
antitoxin,  234 
dose,  immunizing  235 

therapeutic,  235 
injection  (methods),  234 


Bacillus  tetani,  immunizing  substance 

from  cord  and  brain,  234 
infection,  231 

mixed,  232 
isolation,  230 

morphology  and  biology,  228 
pathogenesis,  231 
spores,  229 
toxin,  233,  234 

immunity  against,  233 
of   tetanus    {see    Bacillus    tetani), 

228 
tuberculosis,  187 
agglutination  of,  204 
biology  and  morphology,  187 
bovine,  206 

demonstration  of,  196-198 
animal  inoculation,  198 
feces,  197 
milk,  198 
sputum,  196 
in  tissue-sections,  197 
urine,  197 
effect  of  light  upon,  190 
filtered  cultures,  201 
fowl,  206 
immunization     and      cure      {see 

Tuberculosis),  201 
infection,  192 

gastro-intestinal  tract,  194 

general,  194 

hereditv,  195 

milk,  195 

mixed,  196 

nasal  mucosa,  194 

precautions  against,  193,  194 

respiratory  tract,  193,  194 

skin,  194 
lupus,  194 

susceptibility  to,  193,  194 

tonsils,  194 

with  attenuated  organisms,  194 
occurrence,  187 

organisms  resembling,  209-216 
pathogenesis,  191 
prophylaxis  against   {see    Tuber- 
culosis), 199 
pure  culture  of,  188 
staining  methods,  83-86,  188,  197 
toxin,  201 

immunity  against,  202 
tubercle,  191 

anatomical,  194 

miliary,  192 

tissue,  diffuse,  192 
vitality,  190 


340 


INDEX. 


Bacillus  typhosus  {see  also   Typhoid 
fever),  268 
biology  and  morphology,  268 
cultures^  272 
diagnosis,  277,  278 

Pfeiffer's  phenomenon,  112 
Widal  reaction,  278,  279 
differentiation  from  B.  coli  com- 
munis, 272,  277,  278,  285,  286 
examination  of  water  for,  137,  280 
immunization,  282 
infection,  274 
mixed,  277 
where  found,  276,  277 
organisms  resembling,  283 
pathogenesis,  274 
preventive  inoculation,  282 
staining,  269 
vitality,  271 
typhi    abdominalis     {see     Bacillus 
typhosus),  268 
murium,  329 

pathogenesis,  239 
of     typhoid    fev^r     {see     Bacillus 

typhosus),  268 
violaceus,  143 
of  whooping-cough,  319 
X  {see  Bacillus  icteroides),  289,  290 
of  yellow  fever  {see  Bacillus  icter- 
oides), 289 
Bacteria,  aerobic,  29 
aerogenic,  26 
in  the  air  {see  under  Examination), 

130 
anaerobic,  29,  76 

cultivation  of,  76-79 
association  of,  104 
biology,  28 
capsule,  17 

staining,  88 
cell-membrane,  18 
cell-protoplasm,  17 
cell-wall,  17 

chemical  composition,  17 
chromogenic,  26 
classification,  19,  22,  25 

Migula's,  26 
conditions  influencing  growth,  29 
association,  31,  104 
electricity,  29 
light,  29 
movement,  30 
nutriment,  30 
reaction,  30 
oxygen,  29 
temperature,  31 


Bacteria,       conditions        influencing 
growth,  water,  29 
cultivation  of,  36,  65 
media,  36 
agar-agar,  39 
bouillon,  36 
beef- tea,  36 
blood-agar,  41 
blood-serum,  41 
alkaline,  42 
Loeffler's,  42 
Dunham's  solution,  42 
fresh  eggs,  44 
glycerin  agar-agar,  40 
indol  reaction,  43 
milk,  42 

nutrient  gelatin,  38 
potato,  43 

potato-juice,  44 
sugar-agar,  41 
urine,  44 
description,  17 
distribution,  28 
elimination  from  body,  110 
entrance  to  blood-current,  110 
facultative,  25,  29 
flagella,  18 

staining,  89-91 
granules,  18 
metachromatic,  18 
polar,  18 
microscopic  examination  of  {see  Mi- 
croscopic examination),  80-92 
morphology,  17 
motility,  18 

Brownian  movement,  19 
nitrifying,  34,  44 
non-pathogenic,  25,  101,  141-148 
Bacillus  acidi  lactici,  145 
butyricus,  145 
fluorescens  liquefaciens,  144 
mesentericus  vulgatus,  142 
mycoides,  143 
Oppler-Boas,  146 
prodigiosus,  143 
ramosus,  143 
subtilis,  141 
violaceus,  143 
Bacterium  acidi  lactici,  145 
hay-bacillus,  141 
Leptothrix  buccalis,  147 
epidermidis,  147 
Miller's,  147 
Micrococcus  agilis,  145 

urese,  146 
potato  bacillus,  142 


IN/)E^. 


341 


l^acteria,  non -pathogenic,  Sarciua  au- 
rautica,  146 
lutea,  146 
pulmouum,  146 
veutriculi,  146 
Spirillum  deiiticolum,  147 

rubrum,  146 
Vibrio  berolinensis,  148,  267 
nucleus,  17 
obligative,  25,  29 
parasites,  25 

patliogenic   (in   the    following,   see 
also  the  special  name),  25,  104, 
159-325 
actinomyces,  221 
for  animals  only,  327 

Bacillus  gallinarum,  327 
niurisepticus,  329 
suipestifer,  328 
suisepticus,  328 
typhi  murium,  329 
Bacillus  aerogenes  capsulatus,  312 
anthracis,  299 
anthracoides,  305 
of  anthrax,  299 

symptomatic,  305 
coli  communis.  283 
diphtheria,  236 
dysenteric,  259,  286 
of  Eberth,  268 
enteritidis,  286 
of  Friedlander,  185 
of  glanders,  217 
icteroides,  289 
influenzae,  295 
Kle.bs-Loeffler,  236 
leprae,  209 
of  leprosy,  209 
Lustgarten's,  212 
of  malignant  oedema,  311 
mallei,  217 
paratyphosus,  287 
parotitis,  316 
pestis  bubonicse,  292 
of  Pfeifi'er,  295 
proteus  vulgaris,  314 
pseudodiphtiieria},  247 
pseudotetanus,  235 
pseudotuberculosis,  207 
pvocyaneus,  169 
Shiga's,  286 
smegmatis,  208 
of  syphilis,  212 
tetani,  228 
of  tetanus,  228 
tuberculosis,  187 


Bacteria,  pathogenic.  Bacillus  tuber- 
culosis, bovine,  206 
fowl,  206 
typhi  abdominalis,  268 
of  typhoid  fever,  268 
typhosus,  268 
Van  Niesen's,  214 
of  whooping-cough,  318 
of  yellow  fever,  289 
Bacterium  coli  commune,  259 
lactis,  259 
pestis,  292 
cholera  vibrio,  250 
comma  bacillus,  250 
cultures  of,  69 

Diplococcus  albicans  amplus,  177 
tardissimus,  177 
intracellularis  meningitidis,  178 
lanceolatus,  180 
parotitis,  316 
pneumoniae,  180 
function,  toxin-forming,  104 

vegetative,  104 
Micrococcus  citreus  conglomera- 
tus,  177 
gonorrhoeae,  173 
lanceolatus,  180 
melitensis,  315 
subflavus,  177 
tetragenus,  171 
pneuraobacillus,  186 
pneumococcus,  180 
spirilla  resembling  cholera  germ, 

267 
Spirillum  berolinensis,  148,  267 

choleras,  250 
.    Den  eke,  263 
Dunbarii,  267 
of  JMnkler-Prior,  260 
Metschnikovi,  265 
Spirochaete  Obermeieri,  317 

of  relapsing  fever,  317 
Staphylococcus  pyogenes,  160 
albus,  163 
aureus,  163 
cereus  albus,  164 

flavus,  164 
citreus,  164 
Streptococcus  pyogenes,  164 
brevis,  164 
conglomeratus,  165 
erysipelatis,  164 
longus,  164 
Streptothrix  farcinae,  226 

madurae,  225 
Vibrio  cholerae,  250 


Ui 


INDEX, 


Bacteria,  pathogenic,  Vibrio  proteus, 
260 
tyrogenum,  263 
vibrion  septique,  311 
phlogistic,  103 
photogenic,  26 
products  of,  31,  98 
acids  and  alkalies,  34 
aromatics,  33 
enzymes,  35 
fermentation,  33 
gases,  32 

liquefaction  of  gelatin,  33 
odors,  33 

peptonization  of  milk,  35 
phosphorescence,  32 
pigment,  31 
poisonous,  98 

bacterial  proteins,  100 
cadaveric  alkaloids,  98 
leucomaines,  99 
ptomaines,  98 
toxalbumin,  99 
toxins,  98,  99 
putrefaction,  34 
reduction  of  nitrates,  34 
reproduction,  20 
saprogenic,  26 
saprophytes,  25 
septic,  103 
shape,  22 
size,  19 

in  the  soil  (see  Examination),  138 
specific,  103 
staining  {see  Stains),  81 
toxic,  103 

in  water  (see  Examination),  132 
zymogenic,  26 
Bacterial  proteins,  100 
Bacterium  acidi  lactici,  145 
coli  commune,  259 
lactis,  259 

pestis  (see  Bacillus  pestis),  292 
Basidia,  151 
Beef-tea,  36 
Binary  division,  20 
Blastomyces  (see  Saccharomyces),  156 
Biastomycetic  dermatitis,  158 
Blood,  germicidal  power  of,  116 
Blood-agar.  41 
Blood -serum,  41 
alkaline,  42 
Loeffler's,  42 
Boric  acid,  57 
Bouillon,  36 
Bubonic  plague  (see  Plague),  292 


Cadaveric  alkaloids,  98 
Calcium  hydroxide,  57 
Carbolic  acid,  58 
"  Carbuncle  "  (see  Anthrax),  303 
Cell-membrane,  18 
Chemotaxis,  115 
negative,  115 
positive,  115 
Chlorine,  57 
Cholera,  256 
bacillus  of  (see  Spirillum  cholerae), 

250 
chicken,  327 

bacillus  of,  327 
diagnosis,  258 
hog,  328 

bacillus  of,  328 
immunity,  257 

vaccination,  258 
infection,  256 

water-supply,  256 
morbus,  259 
nostras,  259 
pathogenesis,  256 
Classification  of  bacteria,  19,  22,  25,  26 
Coccus  of  measles,  320 
Coley's  serum,  168 
Colon  group  of  bacilli,  285 
Comma  bacillus  (see  Spirillum  cholerae 

Asiaticse),  250 
Conditions  influencing  growth  of  bac- 
teria (see  under  Bacteria),  29 
Conidia,  149 
Contagious  disease,  102 
Copper  sulphate,  60 
Cryptogam  ia,  17 
thallophytse,  17 
fission-fungi,  17 

hyphomycetes  (moulds),  17 
saccharomycetes  (yeasts),  17 
schizomycetes  (bacteria),  17 
Cultivation  of  anaerobic  bacteria,  76- 
79 
bacteria  (see  Media),  36 
Culture,  of  bacteria  (see  Bacteria,  cul- 
tivation of),  36,  65 
Esmarch  roll,  71 
Klatsch  preparation,  74 
Koch  plate,  67 
media  (see  Media),  36 
sterilization  of  (see  Sterilization), 
45 
Petri  dish,  67 
preliminary  steps,  65 


INDEX. 


343 


Culture,  pure,  45,  65 
smear,  74 
stab,  72 
stroke,  74 
tube,  72 
Cultures,  65 

D. 
Defensive  proteids,  116,  125 
Dermatitis,  blastomycetic,  158 
Diphtheria,  241 
antitoxin,  244 
initial  dose,  245 
injection,  244,  245 
treatment,  244 
use  of,  244 
bacillus  of  {see  Bacillus  diphtherise), 

236 
diagnosis,  bacteriologic,  246 
examination,  243      ^^-' 
immunization,  243   ^"^ 
infection,  241,  242 
membrane  of,  241,  242 
toxin,  242-244 
Diplococci,  22 

Diplococcus  albicans  amplus,  177 
tardissiraus,  177 
of  Class,  321 

intracellularis  meningitidis,  178 
lanceolatus,  -.180 

biology  and  morphology,  180 
immunity,  184 

antipneumococcus  serum,  184 
pathogenesis,  183 
parotitis,  316 

staining,  316 
pneumoniae,  180 
scarlatinae,  321 
Disease,  contagious,  102 

infectious  (seelnfectiousdisease), 101 
Dish  cultures,  67 
Disinfectants,  56 
Disinfection,  45,  52,  61 
of  clothing,  bedding,  etc.,  63 
of  the  dead,  63 
directions  for,  61 
of  excreta,  61 
of  hospital  wards,  62 
of  patient,  63 
of  sick-room,  62 
of  utensils,  63 
Dunham's  solution,  42 


E. 

Ehrlich's    lateral-chain    theory. 
124  •^' 


122 


Ehrlich's  side-chains,  117,  122 
Emulsion,  Pasteur's,  309 
Endospores,  20 
Enzymes,  35,  117,  125 
Esmarch  roll  culture,  71 
Examination,  130-139 
air,  130 

micro-organisms  present,  130 
quantitative  tests,  131 
microscopic,  of  bacteria  {see  Micro- 
scopic examination),  80-4)2 
soil,  138 
boring  apparatus,  139 
made,  138,  139 
water,  132-138 
counting  the  colonies,  135 
fermentation-test,  137 
micro-organisms  present,  132,  133 
for  typhoid  bacillus,  137,  280 
Exanthemata,  320-325 
measles  {see  Measles),  320 
scarlet  fever  {see  Scarlet  fever),  320 
smallpox  {see  Smallpox),  321 
specific  causes,  320 
Experiments  upon  animals  {see  Inocu- 
lation, animal),  93 
in  technique  of   laboratorv  work, 
332-  334 

F. 

Facultative  bacteria,  25,  29 
Farcin  du  bceuf,  226 
Farcy,  219 

buds,  219 
Fermentation,  33 
Fission,  20 
Fission-fungi,  17 

bacteria  {see  also  Bacteria),  17 

hyphomycetes,  17,  149-155 

moulds,  17,  149-155 

saccharomycetes,  17 

schizomycetes,  17 

yeasts.  17 
Flagella,  18 

staining,  89-91 
Fluorescin,  170 
Formaldehyde,  58 

apparatus,  59,  60 
Formalin,  58 
Formalose,  58 
Fungi,  budding,  156-158 

filamentous,  149 
cultivation  of,  155 
examination  of,  153 

fission-  {see  Fission-fungi),  17 
Fungus,  ray,  221 


344 


INDEX. 


G. 

Gelatin,  cultures,  73 

embedded  and  sectioued,  73 

liquefaction  of,  33,  72 

nutrient,  38 
Germicidal  action  of  the  bodv-iuices 
122 

power  of  the  blood,  116 
Germicide,  45.  56 
Glanders  («<;<?  Bacillus  mallei),  217 

bacillus  (see  Bacillus  mallei),  217 
Gonococcus,  173 

biology  and  morphology,  173 

organisms  resembling,  177 

pathogenesis,  176 

staining,  86 
Gram's  method  of  staining,  86 
organisms  not  stained,  87 
stained,  87 
Granules,  merachromatic,  18 

polar,  18 

H. 

Hanging  drop,  80 
Hog  cholera,  328 
Hydrogen  peroxide,  57 
Hydrophobia,  307 
cause,  307 

immunization,  309,  310 
emulsion,  309,  310 
how  made,  310 
injection,  310 
serum,  309 
incubation,  308 
infection,  307,  308 

source  of,  307 
symptoms,  308 
virus,  308 
vitality  of,  309 
where  found,  308 
Hydrophobic  serum,  309 
Hyphai,  149 
Hyphomycetes,  17,  149-155 

I. 

Icterus,  febrile,  314 
Immunity,  106,  113-123 
accidental,  117 
acquired,  114,  117 

theories  explaining,  121 
antitoxins,  122 
exhaustion  theory,  121 
germicidal  action  of  body- j  uices, 
122 


Immunity,  acquired,  theories,  lateral- 
chain  theory,  122 
phagocytosis,  122 
retention  theory,  122 
active,  114 
experimental,  117 
active  form,  118,  119 
by  inert  substances,  120     • 
passive  form,  119 
by  tissue  suspensions,  lir 
inherited,  114 
modification  of,  120 
drugs,  121 

exposure  to  cold,  120 
fatigue,  120 
mixed  infections,  121 
noxious  gases,  121 
other  diseases,  121 
poor  hygiene,  120 
trauma  and  operations,  121 
natural,  114 
germicidal   power  of  the  blood, 

115,  116,  117 
phagocytic  theory  of,  114 
passive,  114 

in    tuberculosis    {see    Tuberculosis, 
immunization  and  cure),  201,  204 
Immunization,  128 
Incubators,  69,  70 
Indol  reaction,  43 

Infection  {see  also  Infectious  disease), 
101-112 
auto-,  102 
avenue  of,  105 
conditions  modifying,  104 
the  germ,  104 
number,  105 
virulence,  104 
attenuation,  104 
increase,  104 
the  individual,  106 
heredity,  107 
immunity,  106 
predisposition,  107 
traumatism,  106 
vital  condition,  106 
definition,  101 
mixed,  101,  121 
phenomena  of,  111 
agglutination,  111 
agglutinin,  112 
anti-bodies,  112 
lysins,  112 

Pfeififer's  phenomenon,  112 
precipitins,  112 
an  ti -sera,  112 


INDEX, 


345 


Infection,  secondary,  102 
sources  of,  107 

blood-current,  110 

conjunctivge,  108 

digestive  tract,  108 

external  ear,  110 

genito-uriuary  tract,  109 

respiratory  passages,  108 

skin,  107 
terminal,  102 
Infectious  disease,  101,  102 

causes,  101,  102,  103 
Koch's  law,  103 

endemic,  103 

epidemic,  103 

pandemic,  103 

sporadic,  103 
Influenza  {see  Bacillus  influenzae),  295 
Inoculation,  74,  93,  118 
animal,  74,  93 ' 

animals  used,  93 

autopsy,  97 

first  steps,  94 

holders,  95 

needle,  94 

syringes,  93 
intravenous,  94 
peritoneal,  94 
subcutaneous,  94 

intralymphatic,  95 

intraocular,  95 

subdural,  95 
of  tubes,  72- 
Intoxication,  119 
Iodoform,  58 


J. 


Jaw,  lumpy,  223 

K. 

Klatsch  preparation,  74 
Koch's  law,  103 
plate  culture,  67 

L.. 

Lateral-chains,  117,  122 
Lepra  bacillus  {see  Bacillus  leprae),  209 
Leprosy,  209,  210 
anaesthetic,  210 
causation,  211 
heredity,  211 
susceptibility,  211 
diagnosis,  211 
distribution,  211 


Leprosy,  inoculation,  211 

nodule,  210,  211 
lepra-cells,  211 
ulceration  of,  210 

varieties,  210 
Leptothrix  buccalis,  147 

epidermidis,  147 

Miller's,  147 
Leucocytosis,  114 
Leucomaines,  99 
Leuconostoc,  23 
Liquefaction  of  gelatin,  33,  72 
Lumbar  puncture,  179,  180 
Lumpy  jaw,  223 
Lupus,  194 

Lymph  {see  Vaccine),  322 
Lysins,  112 
Lyssa  {see  Hydrophobia),  307 

M. 

Macrophages,  114 
Madura  foot,  225 
Malignant  pustule  {see  Anthrax),  303, 

304 
Mallein,  220 
Malta  fever,  315 

micrococcus  of,  315 
Measles,  320 
coccus  of,  320 
contagium  of,  320 
immunity,  320 
Media  {see  Bacteria,  cultivation  of),  36 
Meningococcus,  178 

biology  and  morphology,  178 
diagnosis,  179 

lumbar  puncture,  179,  180 
pathogenesis,  179 
Mercuric  chloride,  56 
Micrococci,  22 
Micrococcus  agilis,  145 
citreus  couglomeratus,  177 
gonorrhoeae  {see  Gonococcus),  173 
lanceolatus,  180 
of  Malta  fever,  315 
meliteusis,  315 
habitat,  315 

morphology  and  biology,  315 
subflavus,  177 
tetragenus,  171 
ureae,  146 
Microphages,  114 

Microscopic  examination  of  bacteria, 
80-92 
anilin  dyes,  81 
cover-glasses,  82 


S46 


INPEX. 


Microscopic  examination  of  bacteria, 
forceps,  83 
hanging-drop,  80 
motility,  80 
preparation  of  stains  {see  Stains), 

81 
slides,  82 

staining  tubercle  bacillus,  83 
stock  solutions,  81 
Microsporon  furfur,  153 
Motility,  18 
Moulds,  17,  149-155 

Achorion  Schoenleinii,  153 
bulbous,  150 
brush,  151 
cultivation  of,  155 
examination  of,  153 
globular,  151 
Microsporon  furfur,  153 
parasitic,  149 
pathogenic,  150 
saprophytic,  149 
segmented,  152 
Trichophyton  tonsurans,  153 
Mouse  septicaemia,  329 

typhus,  329 
Mucorini,  151 
Mumps,  316 

micro-organisms  of,  316 
Museum  specimens,  75 
Mycelium,  149 
Mycetoma,  225 
Mycobacteria,  153 
Mycoderma,  74 

vini,  157 
Mycoprotein,  17 
Mycoses,  151 

Nitrates,  reduction  of,  34 
Nitrifying  bacteria,  34,  44 
Nitromonas,  35 
Non-pathogenic  bacteria,  25 
Nucleases,  117 
Nucleins,  116 
Nucleus,  17 
Nutriment  of  bacteria,  30 


o. 


Obligative  bacteria,  25,  29 

Oidia,  152 

Oidium  albicans,  152 

lactis,  152 
Ophidomonas,  24 
Outfit  for  bacteriology,  331,  332 


P. 

Parasites,  25 
Parotitis,  316 

micro-organisms  of,  316 
Pathogenic  bacteria,  25 
Penicillium  moulds,  151 
Peti'i  dish  culture,  67 
Pfeiffer's  phenomenon,  112 
Phagocytes,  114 
Phagocytosis,  114 
Phenomenon,  PfeiflTer's,  112 
Phylaxins,  125 
Pigments,  31 
Plague,  292 

bacillus  of  {see  Bacillus  pestis),  292 

immunization,  294 

infection,  294 
through  blood,  294 
glands,  294 
lungs,  294 
lymphatics,  294 
skin,  294 

prophylaxis,  294 

in  rats,  293 

serum,  Haffkine's,  294 
Yersin's,  294 

swine,  328 
bacillus  of,  328 
Plasmolysis,  116 
Plate  cultures,  67 
Pneumobaeillus,  185 

morphology  and  biology,  186 

pathogenesis,  186 
Pneumococcus,  180 
Pneumoprotein,  184 
Potassium  permanganate,  56 
Potato,  43 
Potato-juice,  44 
Precipitins,  112 

Products  of  bacteria  {see  under  Bac- 
teria), 31 
Prophylaxis  against  tuberculosis  {see 

Tuberculosis),  199 
Proteids,  defensive,  116,  125 
Proteins,  bacterial,  100 
Protoplasm,  37 

Pseud  odiphtheria  bacillus,  247 
Pseudotetanus  bacillus,  235 
Ptomaines,  98 
Pus,  cocci,  160 
Pustule,     malignant    {see    Anthrax), 

303,  304 
Putrefaction,  34 
Pyocyanin,  170 
Pyoktanin,  57 


INDEX. 


U1 


R. 

Rabies  {see  Hydrophobia),  30'i 
Eay-fungus,  152,  221 
Reaction,  Widal,  111 
Relapsing  fever,  317 
infection,  318 
by  insects,  318 
intrauterine,  318 
pathogenesis,  317 
spirochsete  of,  317 
Reproduction,  20 
binary  division,  20 
fission,  20 
sporulation,  20 
arthrospores,  21 
endospores,  20 
Rhinoscleroma,  227 
Roll  cultures.  71 


S. 

Saccharomyces  cerevisise,  157 
hominis,  157 
raycoderma,  157 
ruber,  158 

subcutaneus  tumefaciens,  157 
Saccharomycetes,  17,  156-158 
Saprsemia,  101 
Saprophytes,  25,  101 
Sarcina,  22 
aurantica,  146 
lutea,  146 
pulmonura,  146 
ventriculi,  146 
Scarlet  fever,  320 
immunity,  321 
.  infection,  320 

micro-organisms,  320 

Diplococcus  scarlatinas,  321 
scales,  320 
Scarlatina  {see  Scarlet  fever),  320 

diplococcus  of,  321 
Schizomycetes  {see  Bacteria),  17 
Septic,  45 
Septicaemia,  105 

mouse,  329 
Serum,  167 

antiamarylic,  291 
anticholera,  257 
antiplague,  294,  295 
Haffkine's.  294 
Yersin's,  294 
antipneuniococcus,  184 
antistreptococcus,  167 
dose.  168 


Serum,  antitoxic,  126,- 128,  129 
antitubercle,  205 
antityphoid,  282 
Coley's,  168 

diphtheria  antitoxin,  243-246 
hydrophobic,_309 
Sanarelli's,  291 
Sliiga's,  287 
for  yellow  fever,  291 
Side-chains,  117,  122 
Silver  nitrate,  56 
Smallpox,  321 
immunity,  322 
infection,  321 

tissue-cells,    microscopic    examina- 
tion of,  321 
spheroidal  bodies,  321 
vaccination   {see  Vaccination),  322, 

323 
vaccine  (see under  Vaccination),  322 
virus,  321,  322 
Smear  cultures,  74 
Soil,  bacteria  in    {see  Examination), 

138 
Sozines,  125 

Specimens,  museum,  75 
Spirilla,  24 

Spirillum  berolinensis,  267 
cholerse  Asiaticae  {see  also  Cholera), 
250 
cultures,  251 
diagnosis,  258 
immunity,  257 
in  man,  258 
vaccination,  258 
infection,  256 
morphology  and  biology,  250- 

255 
organisms  resembling,  260,  267 
pathogenesis,  256 
staining,  251 
vitality,  255 
Den  eke,  263 
denticolum,  147 
Dunbarii,  267 
__Finkler-Prior,  260 

biology  and  morphology,  260- 

263 
pathogenesis,  263 
of  Ganialeia,  265 
Metschnikovi,  265 
rubrum,  146 
Spirochaeta,  24 
of  Obermeier,  317 
Obermeieri,  317 
of  relapsing  fever,  317 


348 


immx. 


Spiromonas,  24 
Sporangium,  149 
Spores,  20 
arthrospores,  21 
endospores,  20 
staining,  87 
Sporidium  vaccinale,  322 
cyst-form,  322 
free  spores,  322 
pure  culture,  322 
Sporulation,  20 
Stab  cultures,  72 
Staining  bacteria  [see  Stains),  81 
Stains,  81 
alkaline  methylene-blue,  82 
anilin  dyes,  81 

water  stains,  82 
for  bacteria  in  tissue,  92 
for  capsules,  88 
for  flagella,  89-91 
for  gonococcus,  86 
for  slides  and  cover-glasses,  82 
for  spores,  87 

for  tubercle  bacillus,  83-86 
Staphylococcus,  23 
cereus  albus,  164 
flavus,  164 
— ^^yogenes,  160 
^Ibus,  163 

epidermidis,  164 
aureus,  163 

biology  and  morphology,  161 
citreus,  164 
habitat,  160 
pathogenesis,  163 
vitality,  163 
Sterigmata,  150 
Sterility,  45 
Sterilization,  45 
of  catgut,  53 
of  dressings,  53 
by  filtration,  50 
of  hands,  54 
by  heat,  45 
autoclave,  50 
dry  heat,  46 
fire,  45 

hot-air  chamber,  47 
intermittent,  48 
fractional,  48 
steam,  47,  49 
sterilizer,  48,  52 
of  infected  wounds,  55 
of  instruments,  52 
of  media,  45-52 
pasteurization,  51 


Sterilization,  of   silk  and  silk-worm 
gut,  53 
of  site  of  operation,  53 
of  tubes,  53 
Streptococcus,  23 
erysipelatis,  164,  167 
L«-pyogenes,  164 
biology,  164 
brevis,  164 
conglomeratns,  165 
longus,  164 
morphology,  164 
pathogenesis,  167 
vitality,  166 
Streptothrix,  24 
actinomyces  {see  Actinomyces),  152, 

221 
farcintB,  153,  226 

injection  into  animals,  227 
Fcersteri,  153 
fungus,  152,  221 
madurse,  153,  225 
mould,  152,  221 
pseudotuberculosa,  153 
Stroke  cultures,  74 
Sugar-agar,  41 
Sugar-bouillon,  38 
Sulphur,  58 
Suppuration,  159 

causes  other  than  cocci,  159 
pus  cocci,  160 

Bacillus  pyocyaneus,  160 
Diplococcus  intracellularis  men- 
ingitidis, 160 
gonococcus,  160 
pneumobacillus,  160 
pneumococcus,  160 
staphylococci,  160 
streptococci,  160 
Swine  plague,  328 
Syllabus  of  laboratory  work,  332 
experiments,  332-334 
study  of  organisms,  335 
technique,  332-334 
Syphilis,  212 
bacillus  of  {see  Bacillus  of  syphilis), 

212 
hereditary,  214 
heredity  in,  215 
immunity,  214 
infection,  214 
lesions,  214 


Tetanus  {see  Bacillus  tetani),  228 
treatment,  234,  235 


INDEX. 


349 


Thrush  fungus,  152 
Tissue-suspensions,  119 
"  T  O,"  204 

preservation  of,  205 
Toxalbumiu,  99 
Toxins,  98,  99,  104 

modified,  124 
"  T  R,"  204 

immunity  in  animals,  204 
preservation  of,  205 
as  a  therapeutic  measure,  205 
use  in  lupus,  205 
Trichophyton  tonsurans,  153 
Tube  cultures,  72 
Tubercle,  191 
anatomical,  194 
bacillus  (see  Bacillus  tuberculosis), 

187 
miliary,  192 
tissue,  diffuse,  192 
Tuberculin,  201 
as  diagnostic  agent,  202 
objections  to,  203 
reaction  in  individuals,  202, 203 
efiect  of,  on  tissues,  202 
injection  of,  203 
ober  (see  "TO"),  204 
preparation  of,  201 
reaction  of,  in  animals,  201 
residue  (see  "TR"),  204 
upper  (see  "TO"),  204 
Tuberculocidin,  205 
Tuberculosis    (see    Bacillus    tubercu- 
losis), 187,  191 
bovine,  205 

bacillus  of,  206 
fowl,  206 

bacillus  of,  206 
immunization  and  cure,  201 
antiphthisin,  205 
antitubercle  serum,  205 
Koch's  researches,  201 
"TR''and  "TO"  (see"TR" 

and  "TO"),  204 
tuberculin  (see    Tuberculin), 

201 
tuberculocidin,  205 
inspection  of  cattle,  200 
pathologic  anatomy  of,  191 
prophylaxis,  199 

disposal  of  sputum,  199 
expectoration,  199 
spit-cups,  199 
excreta,  200 

notification  of  health  authorities, 
200 


Tuberculosis,    prophylaxis,   room    of 
patient,  200 
sexual  intercourse,  200 
pseudo-,  207 
bacillus  of,  207 
Typoid  fever,  268,  274 

antityphoid  serum  for    curative 

purposes,  282 
bacillus  of  (see  Bacillus  typhosus), 

268,  274 
causes,  274-276 

insufficient      disinfection       of 

excreta,  etc.,  275 
unhygienic  surroundings,  276 
diagnosis,  bacteriologic,  277 
puncture  of  spleen,  277 
Widal   reaction    (see  Widal  re- 
action), 278 
epidemics  of,  275 
immunization,  282 
infection,  274,  276 
mixed,  277 
secondary,  277 
preventive  inoculation,  282 

febrile  reaction  from,  282 
prophylaxis,  280 
rules,  281 

V. 

Vaccination,  118,  322,  323 

constitutional  symptoms,  324 

in  cholera,  258 

papule,  324 

precautions,  323 

pustule,  324 

scarification  of  skin,  323 
technique,  323 

site,  323 

times  required,  323 

vaccine  (see  Vaccine),  322 

vesicle,  324 

virus  for,  322 
Vaccine,  322 

bacteria,  322 

bovine,  322 

capillary  tubes,  322 

human,  322 

ivory-point,  322 

sporidium,  322 
Vaccinia,  322 

sporidium,  322 
Vibrio,  24 

berolinensis,  148 

cholerae     (see      Spirillum    cholera^ 
Asiaticaj),  250 


350 


INDEX. 


Vibrio  proteus,  260 

tyrogenum,  263 
Vibrion    septique     of    Pasteur     {see 

Bacillus  of  malignant  cedema),  311 

w. 

Water,  bacteria  in  (see  Examination), 

132 
Weil's  disease,  314 
Whooping-cough,  318 
bacillus  of,  319 
infection,  319 
Widal  reaction,  111,  278 
description  of,  278 
performed,  279 
when  applicable,  278 
Wool-sorters'   disease    (see  Anthrax), 
304 

Y. 

Yeasts,  17,  156-158 


Yeasts,  beer,  157 
cultivation  of,  156 
examination  of,  156 
in  malignant  growths,  158 
pathogenic,  157 
pigment-producing,  157 
in  skin  affections,  158 
species    {see    Saccharomyces),    156, 
157 
Yellow  fever,  289 
causes,  291,  292 

bacillus  (see  B.  icteroides),  289- 

291 
mosquito  (Anopheles),  291 
other   than   B.    icteroides,  291, 
292 
serum,  curative,  291 


Z. 


Zooglcea,  74 


ALPHABETICAL  CATALOQUE  OF  PUBLICATIONS  OF 

LEA    BROTHERS   &   COMPANY, 

706,  708  &  710  Sansom  St.,  Pbiladelphfa 
111  Fifth  Ave.,  New  York 

The  books  in  the  annexed  list  are  for  sale  by  all  booksellers,  or  will  be  sent  carriage 
paid,  to  any  address  in  the  United  States,  on  receipt  of  the  printed  prices. 

ci..a.ssifie:d  inde:x 

ANATOMY.     Gray,  Gerrish,Woolsey,  Huntington,  Eckley,  Treves,   Rockwell. 

BACTERIOLiOGY.      Abbott,  Park,  Zapffe,  Archinard. 

BLiOOD.     Ewing. 

CHEMISTRY.    Simon  (W.),  Simon  (C.  E.),  Attfield,  Martin   &  Rockwell, 

Remsen,  Vaughan  &  Novy,  McGlannan. 
CLIMATOLOGY.     Solly,  Hayem  &  Hare. 
DENTISTRY.     Essig  (Prosthetic),  Kirk  (Operative),  Burchard,  Essig  &  Koenig 

(Metallursrv),  Long,  American  System,  Coleman. 
DERMATOLOGY.     Hyde  &  Montgomery,   Jackson,  Pye-Smith,   Jamieson, 

Hardaway,  Grindon,  Schalek. 
DIAGNOSIS.     Musser,  Hare,  Simon,  Herrick,  Le  Fevre,  Findley,  Arneill. 
DICTIONARIES.     Dunglison,  Duane,  Hoblyn,  Billings  (National). 
DISPENSATORY.     National. 
ELECTRICITY.     Allen,  Potts. 
FOR3IULARir.     Page  .S2. 

FRACTURES  and  DISLOCATIONS.     Stimson,  Pick. 
GYNECOLOGY.     Dudley,  Findley,  Crockett,  Davenport,  American  System, 

Thomas  &   Munde,  Emmet. 
HISTOLOGY.  Dunham, Szymonowicz,  Klein,  Schafer,  Nichols  &  Vale, Wathen. 
HYGIENE.     Harrington,  Egbert,  Richardson. 

LARYNGOLOGY  and  RHINOLOGY.  Posey  &  Wright,  Grayson,  Coakley. 
MATERIA  MEDICA.     Hare,  Culbreth,  Schleif,  Bruce,  Maisch,  Long. 
MEDICAL  JURISPRUDENCE.    Taylor,  D wight. 

NERYOUS  AND  MENTAL  DISEASES.    Starr,  Potts,  Nagel.  Clouston. 
OBSTETRICS,    .lewett,  Davis,  Reynolds  &  Newell,  King,  Playfair,  Evans, 

Manton,  American   System. 
OPHTHALMOLOGY.     Posey  &  Wright,  Veasey,  Suter,  Nettleship,  Norris  & 

Oliver,  Ballenger  &  Wippern,  Juler,  Ailing  &  GrifFen. 
OTOLOGY.     Politzer,  Posey  &  Wright,  Grayson,  Bacon,  Ballenger  &  Wippern, 

Burnett,  Field,  Ferguson. 
PATHOLOGY.      Schmaus,  Green,  Ewing,  Nichols  &  Vale,  Coats. 
PEDIATRICS.     Koplik,  AVilliams,  Tuttle.  Tuley,  Smith. 
PHARMACOLOGY.      Hare,  Cushny,  Culbreth,  Hermann. 
PHARMACY.     Caspari. 

PHYSICS.     Draper,  Martin  &  Rockwell,  McGlannan. 
PHYSIOLOGY.      Hall,    Chapman,    Collins    &    Rockwell,    Foster,    Dalton, 

Guenthers. 
PRACTICE.    Thompson,  Roger,  Malsbary,  Loomis  &  Thompson,  Flint,  Kelly. 
PROGRESSIVE  MEDICINE.     Page  32. 
RADIOTHERAPY.     Allen. 
SEXUAL  DISORDERS.     Morrow,  Taylor. 
STATE  BOARD  EXAMINATION  SERIES.     Page  26. 
SURGERY,     von  Bergniann,  Park,  Brewer,  Roberts,   Cheyne   &   Burghard, 

Treves,  Ashhurst,  Gallaudet,  Richardson,  Magee  &  Johnson,  Wharton. 
SURGERY— OPERATIVE.    Stimson,  Wharton,  Treves,  Smith. 
SURGERY- ORTHOPEDIC.    Whitman. 
THERAPEUTICS.    Hare,  Schleif,  Cnshny,  Fothergill,Whitla,  Hayem  &  Hare, 

Bruce,  Tirard,  Long. 
URINARY  DISEASES.    Taylor,  Roberts,  Black. 

VENEREAL  I>ISEASES.  Taylor,  Morrow,  Hayden,  Schmidt,  Fuller,  Cornil. 
VISITING  LIST.    Page  32. 
7-1-04 


2      Lea  Brothers  &  Co.,  Philadelphia  and  New  York. 


ABBOTT  (A.  C).  PRINCIPLES  OF  BACTERIOLOGY:  a  Practical 
Manual  for  Students  and  Physicians.  Sixth  edition  thoroughly 
revised  and  greatly  enlarged.  12mo.  636  pages,  with  111  engravings, 
of  which  26  are  colored.    Cloth,  $2.75,  nei. 


as  the  most  suitable  work  from  which 
to  gain  a  knowledge  of  its  science. 
It  is  accurate,  concise,  clear  and  at- 
tractive.— The  New  York  State  Jour- 
nal of  Medicine. 


This  book  has  been  adopted  as  a 
standard  text-hook  on  bacteriology 
in  nearly  all  the  medical  colleges 
in  the  United  States,  and  not  only 
this,  but  it  has  been  also  generally 
accepted  by  the  medical  profession  I 

ALiIiEN  (CHARLES  W.).  RADIOTHERAPY,  PHOTOTHERAPY 
AND  HIGH  FREQUENCY  CURRENTS.  The  Medical  and  Sur- 
gical Applications  of  Radiology  in  Diagnosis  and  Treatment.  Octa- 
vo, 618  pages,  131  engravings  and  27  full-page  colored  plates.    Cloth, 

$4.50,  net. 

AliLEN  (HARRISON).  A  SYSTEM  OF  HUMAN  ANATOMY; 
WITH  AN  INTRODUCTORY  SECTION  ON  HISTOLOGY,  by 
E.  O.  Shakespeare,  M.D.  Comprising  813  double-columned  quarto 
pages,  with  380  engravings  on  stone,  109  plates,  and  241  wood  cuts 
in  the  text.     One  volume,  cloth,  $23. 

AliLiING  (ARTHUR  N.)  and  GRIFFEN  (O.  A.).  AN  EPITOME 
OF  EYE  AND  EAR  DISEASES.  12mo,  about  225  pages,  with  82 
engravings.  Cloth  $1.00,  i^et.  Shortly.  See  Lea's  Series  of  Medical 
Epitomes,  page  18. 

AMERICAN  SYSTEM  OF  PRACTICAL  MEDICINE.  A  SYS- 
TEM OF  PRACTICAL  MEDICINE.  In  contributions  by  Various 
American  Authors.  Edited  by  Alfred  L.  Loomts,  M.D.,  LL.D., 
and  W.  Oilman  Thompson,  M.  D.  In  four  very  handsome  octavo 
volumes  of  about  900  pages  each,  fully  illustrated.  Complete  work 
now  ready.  Per  volume,  cloth,  $5;  leather,  $6;  half  Morocco,  $7. 
For  sale  by  subscription  only.     Prospectus  free  on  application. 

AMERICAN  SYSTEM  OP  DENTISTRY.  In  treatises  by  various 
authors.  Edited  by  Wilbur  F.  Litch,  M.D.,  D.D.S.  In  three  very 
handsome  super-royal  octavo  volumes,  containing  about  3200  pages, 
with  1873  illustrations  and  many  full-page  plates.  Per  vol.,  cloth, 
$6 ;  leather,  $7.  For  sale  by  subscription  only.  Prospectus  free  on 
application  to  the  Publishers. 

AMERICAN  SYSTEMS  OF  GYNECOLOGY  AND  OBSTET- 
RICS. By  eminent  American  specialists.  Gynecology  edited  by 
Matthew  D.  Mann,  A.M.,  M.D.,  and  Obstetrics  edited  by  Barton 
C.  Hirst,  M.D.  In  four  octavo  volumes,  comprising  3612  pages, 
with  1092  engravings,  and  8  colored  plates.  Per  volume,  cloth,  $5 ; 
leather,   $6;   half  Russia,  $7.     Prospectus  free  on  request. 

AMERICAN   TEXT-BOOK    OF    OPERATIVE  DENTISTRY. 

Edited  by  Edward  C.  Kirk,  D.D.S.,  Professor  of  Clinical  Dentistry, 

Department  of  Dentistry,  University  of  Pennsylvania.    Second  edition. 

857  pages,  897  engravings.    Cloth,  $6;  leather,  $7,  net. 

Written  by  a  number  of  practi-  j      It  is  replete  in  every  particular 

tioners  as  well  known  at  the  chair  |  and  treats  the  subject  in  a  progressive 

as  in  journalistic  literature,  many  of    manner.     It   is  a  book  that  every 


them  teachers  of  eminence  in  our 
colleges.  It  should  be  included  in 
the  list  of  text-books  set  down  as 
most  useful  to  the  college  student. — 
The  Dental  News. 


progressive  dentist  should  possess, 
and  we  can  heartily  recommend  it 
to  the  profession. — The  Ohio  Dental 
Journal. 


Lea  Brothers  &  Co.,  Philadelphia  and  New  York.       3 

AMERICAN  TEXT-BOOK  OF  ANATOMY.     See  Gerrish,  page  11. 

A3IER1CAN  TEXT-BOOK  OF   DENTAL   PATHOLOGY.     See 

Burchard,  page  5. 

AMERICAN  TEXT-BOOK  OF  DENTAL  MATERIA  3IEDICA 
AND  THERAPEUTICS.     See  Long,  page  18. 

AMERICAN  TEXT-BOOK  OF  PROSTHETIC  DENTISTRY. 

In  Contributions  by  Eminent  American  Authorities. 

Edited  by  Charles  J.  Essig,  M.D.,  D.D.S.,  Professor  of  Mechanical 
Dentistry  and   Metallurgy,  Department  of  Dentistry,  University  of 
Pennsylvania,  Philadelphia.    Second  edition.    807  pages,  1089  engrav- 
ings.    Cloth,  $6 ;  leather,  $7,  net. 
No  more  thorough  production  will 


be  found  either  in  this  country  or  in 
any  country  where  dentistry  is  un 
derstood  as  a  part  of  civilization.— 
The  Intemaiiof\<il  Dental  JmimaL 


It  is  up  to  date  in  every  particular. 
It  is  a  practical  course  on  prosthetics 
which  any  student  can  take  up  dur- 
ing or  after  college. — Dominion  Den- 
ial Journal. 


A  TREATISE   ON   SURGERY  BY  AMERICAN  AUTHORS. 

FOR  STUDENTS  AND  PRACTITIONERS  OF  SURGERY  AND 
MEDICINE.    Edited  by  Roswell  Park,  M.D.     See  page  21. 

ARCHINARD  (P.  E.).  AN  EPITOME  OF  MICROSCOPY  AND 
BACTERIOLOGY.  12mo,  240  pages,  with  74  illustrations.  Cloth,  $1, 
net.     Lea's   Series   of  Medical  Epitomes.     See  page  18. 

ARNEILL  (JAMES  R.).  AN  EPITOME  OF  CLINICAL  DIAG- 
NOSIS AN  D  URINALYSIS.  See  Lea's  Series  of  Medical  Epitomes. 
Page  18. 

ASHHURST  (JOHN,  JR.).  THE  PRINCIPLES  AND  PRACTICE 
OF  SURGERY.  For  the  use  of  Students  and  Practitioners.  Sixth 
and  revised  edition.  In  one  large  and  handsome  octavo  volume  of 
1161  pages,  with  656  engravings.   Cloth,  $6;  leather,  $7. 


As  a  masterly  epitome  of  what  has 
been  said  and  done  in  surgery,  as  a 
succinct  and  logical  statement  of  the 
principles  of  the  subject,  as  a  model 


text-book,  we  do  not  know  its  equal. 
It  is  the  best  single  text-book  of 
surgery  that  we  have  yet  seen  in  this 
country. — New  York  Post- Graduate. 


ATTFDELD  (JOHN).  CHEMISTRY ;  GENERAL,  MEDICAL  AND 
PHARMACEUTICAL.  Sixteenth  edition,  specially  revised  by  the 
Author  for  America.  In  one  handsome  12mo.  volume  of  784  pages, 
with  88  illustrations.    Cloth,  $2.50,  net. 

It  is  replete  with  the  latest  inform- !  or  in  general  practice. —  The  Pitts- 
ation,  and  considers  the  chemistry  of  |  hurg  Medical  Review. 
every  substance  recognized  officially  ' 

BACON  (GORHAM).  ON  THE  EAR.  Third  edition.  One  12mo. 
volume,  430  pages,  120  engravings  and  7  colored  plates.  Cloth, 
net,  $2.25. 


It  is  the  best  manual  upon  otology. 
An  intensely  practical  book  for  stu- 
dents of  medicine — Cleveland  Jour- 
nal of  Medicine. 

The  book  is  practically  a  new  one 
and  thoroughly  up-to-date — a  book 


which  will  be  found  of  the  highest 
utility  to  both  the  medical  student 
and  practitioner.  This  book  is  sure 
to  commend  itself  to  the  specialist  as 
well. — St.  Louis  Medical  and  Sur- 
gical .Journal. 


BARNES  (ROBERT  AND  FANCOURT).  A  SYSTEM  OF  OB- 
STETRIC MEDICINE  AND  SURGERY.  Octavo,  872  pages,  with 
231  illus.    Cloth,  $5 ;  leather,  $6. 


4       Lea  Brothers  &  Co.,  Philadelphia  and  New  York. 

BAL.L.ENGER  (W.  Li.)  AND  WIPPERN  (A.  G.).  A  POCKET 
TEXT-BOOK  OF  DISEASES  OF  THE  EYE,  EAR,  NOSE  AND 
THROAT.  In  one  handsome  12mo.  volume  of  525  pages,  with  148 
illustrations,  and  6  colored  plates.  Cloth,  $2.00,  we<;  limp  leather, 
$2.50,  net.     See  LecOs  Series  of  Pocket  Text-books,  p.  18. 


Like  the  other  volumes  of  this 
series,  this  is  compendious  and  re- 
plete with  information  of  the  sort 
needed  by  the  student  and  practi- 
tioner. The  authors  are  fully  qualified 


to  write  upon  the  subjects  they  have 
chosen,  and  they  have  done  so  in  a 
manner  which  makes  the  book  a 
valuable  one.  —  St.  Louis  Medical 
and  Surgical  Reporter. 


BARTHOLOW  (ROBERTS).  CHOLERA;  ITS  CAUSATION,  PRE- 
VENTION AND  TREATMENT.  In  one  12mo.  volume  of  127  pages, 
with  9  illustrations.     Cloth,  $1.26. 

BERGMANN'S  SURGERY.     See  von  Bergmann,  page  30. 

BlLiLINGS  (JOHN  S.).  THE  NATIONAL  MEDICAL  DICTIONARY. 
Including  in  one  alphabet  English,  French,  German,  Italian  and 
Latin  Technical  Terms  used  in  Medicine  and  the  Collateral  Sciences. 
In  two  octavo  volumes  containing  1574  pages  and  two  colored  plates. 
Per  volume,  cloth,  $6 ;  leather,  $7. 

BLACK  (D.  CAMPBELiL).      THE    URINE    IN    HEALTH    AND 

DISEASE,  AND  URINARY  ANALYSIS,  PHYSIOLOGICALLY 

AND  PATHOLOGICALLY  CONSIDERED.    In  one  12mo.  volume 

of  256  pages,  with  73  engravings.     Cloth,  $2.75. 

A  concise,  yet  complete  manual,  [  tical  and  clinical  standpoint. — The 

treating  of  the  subject  from  a  prac-    Ohio  Medical  Journal. 

BLiOXAM  (C.  li.).  CHEMISTRY,  INORGANIC  AND  ORGANIC. 
With  Experiments.  New  American  from  the  fifth  London  edition. 
In  one  handsome  octavo  volume  of  727  pages,  with  292  illustrations. 
Cloth,  $2  ;  leather,  $3. 

BREWER  (GEORGE  E.).    A  TEXT-BOOK  OF  THE  PRINCIPLES 
AND  PRACTICE  OF  SURGERY.     Octavo,  700  pages,  280  engrav- 
ings, 7  colored  plates.     Cloth,  $4 ;  leather,  $5,   net ;   half   Morocco, 
$5.50,  net.     Just  ready. 
This  volume  presents  the  essential  I  heartily  commend  the  book  not  only 

facts  of  surgery  in  a  comprehensive,  1  to  students  but  also  to  practitioners. 

clear  and  concise  manner.     The))ook  \  — St.  Paul  MedicalJ  ournal. 


is  a  scientific  exposition  of  modern 
surgery,  and  the  reviewer  has  no 
hesitancy  in  saying  that  it  is  the 
best  surgical  text-book  in  print  by 
an  American  author.  The  author 
presents  a  practical,  common-sense 
and  yet  highly  scientific  work.     We 


The  author's  intensely  ])ractical 
treatment  of  this  comprehensive  sub- 
ject, combined  with  brevity  and 
definite  clearness  of  statement,  at 
once  compels  the  reader's  attention 
and  bespeaks  the  success  of  the  work. 
— Medical  Review  of  Reviews. 


BRUCE  (J.  MITCHELL.).  MATERIA  MEDICA  AND  THERA- 
PEUTICS. Sixth  edition.  In  one  12mo.  volume  of  600  pages. 
Cloth,  $1.50,  net.    See  Student's  Series  of  Manuals,  page  27. 


known    and    appreciated. — Medical 
Revieiv  of  Reviews. 


This  new  edition  increases  the 
value  and  more  firmly  establishes 
the  reputation   of   a  work  already 

BRUCE   (J.  MITCHEIiLi).    PRINCIPLES  OF  TREATMENT.     In 

one  octavo  volume  of  625  pages.     Cloth,  $3.75,  net. 


One  of  the  most  useful  books  in 
which  the  practitioner  can  invest. 
It  is  a  book  worthy  of  reading  from 


cover  to  cover. —  Virginia  Medical 
Semi- Monthly. 


Lea  Bkothkrb  &  Co.,  Philadblphia  and  New  Yoek.       6 


BRYANT  (THOMAS).  THE  PRACTICE  OF  SURGERY.  Fourth 
American  from  the  fourth  English  edition.  In  one  imperial  octavo  vol- 
ume of  1040  pages,  with  727  illustrations.    Cloth,  $6.50 ;  leather,  $7.50. 

BURCHARD  (HENRY  H.).  DENTAL  PATHOLOGY.  New  (2nd) 
edition,  tlioroui^hly  revised  by  Otto  E.  Euglis,  D.D.S.  Handsome 
octavo,  about  600  pages,  with  about  450  illustrations.    Ready  shortly. 

BURNETT  (CHARLES  H.).  THE  EAR :  ITS  ANATOMY,  PHYSI- 
OLOGY AND  DISEASES.  A  Practical  Treatise  for  the  Use  of 
Students  and  Practitioners.  Second  edition.  In  one  8vo.  volume  of 
580  pages,  with  107  illustrations.     Cloth,  $4 ;  leather,  $5. 

CARTER  (R.  BRUDENEIili)  AND  FROST  (W.  ADAMS).  OPH- 
THALMIC SURGERY.  In  one  pocket-size  12mo.  volume  of  559 
pages,  with  91  engravings  and  one  plate.  Cloth,  $2.25.  See  Series  of 
Clinical  Manuals,  page  25. 

CASPARI   (CHARIiES   JR.).     A  TREATISE  ON  PHARMACY. 

For  Students  and  Pharmacists.     Second  edition.      In  one  handsome 

octavo  volume  of  774  pages,  with  301  illustrations.     Cloth,  $4.25  nei. 

In  a  single  comprehensive  volume  '  ers  instruct  from  it   with   economy 

he  presents  tbe  body  of  information    in    time    and    eflbrt.     Pharmacists 

which  to-day  constitutes  the  science  .  will  find  it  a  most  useful  guide  in 

and  practice  of  pharmacy  in  its  pre-    the  operations  of  their  calling  and 

sent   advanced   state.     It   is  homo-    in   the   interpretation  of  the  Phar- 

geneous,  uniform,  clear  and  accur-    macopa^a. — The  San  Frniiciscoavd 

ate.     Students  can  learn  and  teach-  i  Pacific  Driufgist. 

CHAPMAN  (HENRY  C).  A  TREATISE  ON  HUMAN  PHYSI- 
OLOGY. Second  edition.  In  one  octavo  volume  of  921  pages, 
with  595  illustrations.     Cloth,  $4.25 ;  leather,  $5.25,  net. 


In  every  respect  the  work  fulfils 
its  promise,  whether  as  a  complete 
treatise  for  the  student  or  as  an  ad- 


mirable work  of  reference  for  the 
physician. — North  Carolina  Medical 
Journal. 


CHARLES  (T.  CRANSTOUN).  THE  ELEMENTS  OF  PHYSIO- 
LOGICAL AND  PATHOLOGICAL  CHEMISTRY.  Octavo,  451 
pages,  with  38  engravings  and  1  colored  plate.     Cloth,  $3.50. 

CHEYNE  (W.  W.)  AND  BURGHARD  (F.  F.).  SURGICAL 
TREATAIENT.  In  seven  octavo  volumes,  containing  2908  pages 
with  827  engravings.  Volume  I.,  cloth,  $3.00  net.  Volume  II.,  cloth, 
$4.00  net.  Vol.  Ill,  cloth,  $3.50,  net.  Vol.  IV.,  cloth,  $3.75,  net. 
Vol.  v.,  cloth,  $5.00,  nel.  Vol.  VI.,  cloth,  $5.00,  nei.  Vol.  VII., 
cloth,  $5.75,  net. 

The  book  differs  from  all  other  after  operation,  including  the  con- 
works  on  surgery  in  the  English  duct  of  the  treatment  in  the  face 
language  by  confining  itself  strictly  \  of  any  of  the  emergencies  of  surgi- 
to  practical  considerations.  There  eal  pratice.  is  fully  set  forth.  The 
is  no  theory  of  disease  or  its  causa-  i  vast  material  on  which  the  authors 
tion— nothing  but  the  treatment  of  have  drawn  for  their  deductions 
patients  suffering  from  surgical  dis-  gives  the  book  an  unusual  value. 
ease,  once  the  diagnosis  is  made.  —Medical  Xeios. 
The  treatment  of  patients  before  and 

CLELAND  (JOHN).  A  DIRECTORY  FOR  THE  DISSECTION  OF 
THE  HUMAN  BODY.    In  one  12mo.  vol.  of  178  pages.    Cloth,  $1.25. 

CLINICAL  MANUALS.    See  Series  of  Clinical  Manuals,  page  25. 


6      Lea  Beothkrs  &  Co.,  Philadblphia  and  New  York. 


CliOUSTON  (THOMAS  S.).    CLINICAL  LECTURES  ON  MENTAL 

DISEASES.     New  (5th)  edition.     In  one  octavo  volume  of  750  pages, 
with  19  colored  plates.     Cloth,  $4.25,  net. 

COAKL.EY  (CORNELIUS  G.).  THE  DIAGNOSIS  AND  TREAT- 
MENT OF  DISEASES  OF  THE  NOSE,  TPIROAT.  NASO- 
PHARYNX AND  TRACHEA.  Second  edition.  In  one  12mo. 
volume  of  656  pages,  with  103  engravings  and  4  colored  ])lates.  Cloth, 

$2.75.  net. 


It  is  the  best  condensed  manual 
that  has  recently  appeared. — Boston 
Medical  and  Surgical  Journal. 

Dr  Coakley  devotes  especial  at- 
tejition  to  the  practical  points,  such 
as  ex  imination,  diagnosis  and  treat- 
ment, thereby  making  a  valuable 
acquisition   to    the    library   of   the 


student  and  general  practitioner.  A 
special  chapter  on  therapeutics  has 
been  added,  which  contains  a  classifi- 
cation of  drugs  according  to  their 
local  action,  and  a  number  of  useful 
prescriptions,  with  indications  as  to 
their  use. — The  Kansas  City  Med- 
ical Index-Lancet. 


COATS  (JOSEPH).  A  TREATISE  ON  PATHOLOGY.  In  one  vol* 
of  829  pages,  with  339  engravings.     Cloth,  $5.50 ;  leather,  $6.50. 

COLEMAN  (ALFRED).    A  MANUAL  OF  DENTAL  SURGERY 

AND  PATHOLOGY.  With  Notes  and  Additions  to  adapt  it  to  Amer- 
ican Practice.  By  Thos.  C.  Stellwagen,  M.A.,  M.D.,  D.D.S.  In  one 
handsome  octavo  vol.  of  412  pages,  with  331  engravings.    Cloth,  $3.25. 

COLLINS  (C.  F.)  and  DAVIS  (F.).  A  POCKET  TEXT  BOOK 
OF  MEDICAL  DIAGNOSIS.  Preparing.  See  Lea's  Series  of 
Pocket  Text-Books,  page  18. 

COLLINS  (H.  D.)  AND  ROCKWELL  (W.  H.).  A  POCKET 
TEXT-BOOK  OF  PHYSIOLOGY.  12mo.  of  316  pages,  with  153 
illustrations.  Cloth,  $1.50;  flexible  red  leather,  $2.00,  net.  See 
Lea's  Series  of  Pocket  Text-books,  page  18. 


practitioner  with  the  advances  in 
this  subject. — The  Physician  and 
Surgeon. 


Well  written  and  up  to  date.  It 
is  a  manual  admirably  adapted  to 
teach  the  beginner  the  essentials  of 
physiology,    and    to    acquaint    the 

OONDIE  (D.  FRANCIS).  A  PRACTICAL  TREATISE  ON  THE  DIS- 
EASES OF  CHILDREN.  Sixth  edition,  revised  and  enlarged.  In 
one  large  8vo.  volume  of  719  pages.     Cloth,  $5.25. 

CORNHi  (V.).  SYPHILIS :  ITS  MORBID  ANATOMY,  DIAGNO- 
SIS AND  TREATMENT.  Translated,  with  Notes  and  Additions,  by 
J.  Henry  C.  Simes,  M.D.  and  J.  William  White,  M.  D.  In  one 
8vo.  volume  of  461  pages,  with  84  illustrations.     Cloth,  $3.75. 

CROCKETT  (M.  A.).      A  POCKET  TEXT-BOOK  OF  DISEASES 
OF    WOMEN.     In  one  handsome  12mo.  volume  of  368  pages,  with 
107   illustrations.      Cloth,   $1.50,   net;    flexible    leather,   $2.00,   net. 
See  Lea's  Series  of  Pocket  Text-hooks,  page  18. 
This  is,  like  all  the  other  manuals 

in  this  series,  a  most  excellent  guide 

for  students  and  a  handy  reference 


book    for   practitioners. — St.  Louit 
Medical  and  Surgical  Journal. 


CROOK    (JAMES      K.)    ON    MINERAL     WATERS     OF     THE 
UNITED  STATES.     Octavo,  575  pages.     Cloth,  $3.50,  net. 
In  such  a  book  as  this  the  medical    of  every  water  of  any  known  medici- 
profession  will  find  a  wonderful  ally ;    nal    properties. —  The    Louisville 
it  is  remarkably  complete  in  every    Monthly  Journal. 
detail,  giving  the  results  of  analyses  j 


Lea  Beothers  &  Co.,  Philadelphia  and  New 


CULBRETH  (DAVID  M.  R.).    MATERIA  MEDICA  AND  PHAR- 
MACOLOGY.     Third  edition.      In   one   handsome  octavo  volume 
of  905  pages,  with  478  illustrations.     Cloth,  $4.75,  net. 
A  systematic  and  thorougli  treatise  on  the  entire  Materia  Medica, 

animal,  vegetable  and  mineral.     In  detail  and  abundance  of  information, 

as  well  as  richness  of  illustration,  this  convenient  volume  has  no  parallel 

on  its  subject. 

CUSHNY    (ARTHUR  R.).   TEXT-BOOK  OF  PHARMACOLOGY. 

Third  edition.     Handsome  8vo.,   750   pages,   with  52   illustrations. 

Cloth,  $3.75,  net ;   leather,  $475,  net. 
The  best  exposition  of  our  knowl-    acquainting  themselves  with  the  very 
edge  of  pharmacology  which  has  yet    latest  knowledge  on  this  very  im- 
been  given  to  the  mediral   public,    portant  subject. — The  Montreal  Med- 
We  can  cordially  recommend  it  to    ical  Journal. 
all  our  readers  who  are  desirous  of  ^ 

DALTON  (JOHN  C).  A  TREATISE  ON  HUMAN  PHYSIOLOGY. 
Seventh  edition.  Octavo,  722  pages,  with  252  engravings.  Cloth, 
$5 ;  leather,  $6. 

DOCTRINES  OF  THE  CIRCULATION  OF  THE  BLOOD.  In 

one  handsome  12mo.  volume  of  293  pages.     Cloth,  $2. 

DAVENPORT  (F.  H.).      DISEASES  OF  WOMEN.      A   Manual  of 
Gynecology.      For    the  use  of  Students  and    Practitioners.     Fourth 
edition.     In  one  handsome   12mo.   volume    of   402    pages,  with   154 
illustrations.     Cloth,  $1.75,  net. 
Dr.    Davenport    has    the    happy  j  knowing,  and  presents  these  princi- 
faculty  of  selecting  just  those  points    pies  in  a  clear,  concise  and  thorough 
in  gynecological  therapeutics    and  !  manner.     The  book  can  be  highly 
surgery  which  the  student  and  junior  I  commended. —  The  Medical  Age. 
practitioner  most  stand  in  need  of  1 

DAVIS  (EDWARD  P.).  A  TREATISE  ON  OBSTETRICS.  FOR 
STUDENTS  AND  PRACTITIONERS.  New  (2nd)  edition, 
thoroughlv  revised;  In  one  very  handsome  octavo  volume  of  800 
pages,  witli  274  engravings  and  39  full-page  plates  in  colors  and  mono- 
chrome. Cloth,  $5.00,  net ;  leather,  $6.00,  net.  Just  ready. 
The  author  has  fully  utilis'.ed  the  opportunity  presented  by  the  demand  for 

another  edition  of  his  well  known  work,  and  has  subjected  it  to  a  thorough 

revision.      It  is  a  succinct  and   clear  presentation  of  modern  obstetrics, 

with  ample  illustration. 

DAVIS  (F.  H.).  LECTURES  ON  CLINICAL  MEDICINE.  Second 
edition.     In  one  12mo.  volume  of  287  pages.     Cloth,  $1.75. 

DAYTON  (HUGHES).  AN  EPITOME  OF  THE  PRACTICE  OF 
MEDICINE.     See  Lea's  Series  of  Medical  Epitomes,  page  18. 

DE  LiA  HECHE'S  GEOLOGICAL  OBSERVER.  In  one  large  octavo 
volume  of  700  pages,  with  300  engravings.     Cloth,  $4. 

DE  SCHWEINITZ  (GEORGE  E.).  THE  TOXIC  AMBLYOPIAS. 
Their  Classification,  History,  Symptoms,  Pathology  and  Treatment. 
Very  handsome  octavo,  240  pages,  46  engravings,  and  9  full-page 
plates  in  colors.     De  luxe  binding,  $4,  net. 

DRAPER  (JOHN  C).  MEDICAL  PHYSICS.  A  Text-book  for  Stu- 
dents  and  Practitioners  of  Medicine.  In  one  handsome  octavo  volume 
of  734  pages,  with  376  engravings.     Cloth,  $4. 

DRUITT  (ROBERT).  THE  PRINCIPLES  AND  PRACTICE  OF 
MODERN  SURGERY.  Twelfth  Edition.  Octavo,  965  pages,  with 
373  engravings.     Cloth,  $4;  leather,  $5. 


8      Lea  Brothers  &  Co.,  Philadelphia  and  New  York. 

DUANE  (ALEXANDER).  A  DICTIONARY  OF  MEDICINE  AND 
THE  ALLIED  SCIENCES.  Comprising  the  Pronunciation,  Deriva- 
tion and  Full  Explanation  of  Medical,  Dental,  Pharmaceutical  and 
Veterinary  Terms.  Together  with  much  Collateral  Descriptive  Mat- 
ter. Numerous  Tables,  etc.  Fourth  edition,  with  appendix.  Square 
octavo  of  688  pages,  with  8  colored  plates  and  thumb  index.  Cloth, 
$3.00.  net ;  limp  leather,  $4.00.  net. 
It  is  one  of  the  modern  marvels   purse.     For  the  student  and   busy 

that  such  a  vast  aggregate  of  schol-    practitioner  it  is  decidedly  the  best 

arly  knowledge  can  be  placed  with-   book    in    its    line. — TJie    l^outhem 

in  the  command  of  a  very  modest ;  Practitioner. 

DUDLEY    (E.    C).      THE    PRINCIPLES    AND    PRACTICE    OF 
GYNECOLOGY.     New  (4th)  edition,  thoroughly  revised.     Handsome 
octavo  of  770  pages,  with  420  illustrations  in  black  and  colors,  and 
16  colored  plates.     Cloth,  $5.00,  net;  leather,  $6.00,  net;  half  Moroc- 
co, $6.r)0,  net.    Just  ready. 
The  marked  success  of  this  book  is  owing  to  its  reduction  of  (iynecology 
to  a  rational  basis  and  its  consequent  simplification  of  the  subject.     It 
requires  a  master's  hand  to  simplify  in  this  way,  but  once  done,  others 
can  attain  the  mastery.    Everything  in  this  work  bears  on  practice.     Tlie 
author  has  again    revised   the   boot  thoroughly  to  date,  enriching  the 
already  notable  series  of  illustrations  in  black  and  colors,  with  many  new 
engravings  and  plates,  especially  emphasizing  those  showing  the  steps  of 
operations.     In  this  new  edition  every  illustration  is  original. 

DUNGLISON  (ROBLEY).   A  DICTIONARY  OF  MEDICAL  SCI- 
ENCE.     Containing  a  full  explanation  of  the  various  subjects  and 
terms  of  Anatomy,  Physiology,  Medical  Chemistry,  Pharmacy,  Phar- 
macology, Therapeutics,  Medicine,  Hygiene,  Dietetics,  Pathology,  Sur- 
gery, Ophthalmology,  Otology,  Laryngology,  Dermatology,  Gynecol- 
ogy, Obstetrics,  Pediatrics,  Medical  Jurisprudence,  Dentistry,  etc.,  etc. 
By  ROBLEY  DuNGLiSON,  M.  D.,  LL.  D.,  late   Professor  of  Institutes 
of  Medicine  in  the  Jefferson  Medical  College  of  Philadelphia.       New 
(23d)  edition,  thoroughly  revised  by  Thomas  L.  Stedman,  M.D., 
In  one  magnificent  imperial  octavo  volume  of  1220  pages  with  577 
illustrations,  including  84  full  page  plates  mostly  in  colors.    With 
thumb  letter  index.     Cloth,  $8,  net;  leather,  ij^O,  net;  half  Morocco, 
$9.50,  net. 
The  name  of   Dunglison    stands 
forth  as  that  of  the  greatest  medical 
lexicographer    of     the    English 
language.     For  seventy-five    years 
this  work  has  been   the    standard 
dictionary    used    by    the    English- 
speaking  medical  world,  and   now 
in   its  twenty -third  edition  it  is  a 
pleasure  to  realize  tliat  it  remains 
fully  up  to  the  standard  of  the  mo«t 
modern   requirements.  —  American 
Journal  of  the  Medical  Sciences. 

Divnglison^s  Medical  Dictionary 
remains  what  it  has  always  been, 
the  criterion  of  medical  lexico- 
graphy.— Medical  Review  of  Re- 
views. 


The  standard  work  of  its  kind. — 
American  Practitioner  and  News. 

Along  with  Gray's  Anatomy, 
Dunglison' s  Dictionary  has  stood 
the  test  of  time  and  practical  value. 
It  stands  at  the  h^nA.— Clinical 
Review. 

It  has  held  the  first  place.  Others 
have  appeared  and  vanished.  Dung- 
lison became  an  institution  in 
medicine.  It  is  a  thorough  ex- 
emplar of  twentieth  century  medi- 
cine. Complete,  thorough,  clear. 
Pre-eminent  among  medical  diction- 
aries.— St.  Louis  Medical  and  Siir- 
gical  Journal. 


DUNHAM  (EDWARD    K.).       MORBID    AND    NORMAL     HIS- 
TOLOGY.    Octavo,  450  pages,with  363  illustrations.  Cloth,  $3.25,  net. 
The  best  one- volume  text  or  refer- 1  of  published  in  America. —  Virginia 
ence  book  on  histology  that  we  know  '  Medical- Semi •3Ionthly. 


Lea  Brothers  &  Co.,  Philadelphia  and  New  York.       9 

DUNHAM  (EDWARD  K.)  NORMAL  HISTOLOGY.  New  (3rd)  and 
revised  edition.  Octavo,  334  pages,  with  2fi0  illustrations.  Cloth, 
$2,75,  net.     Just  ready.     A  notice  of  the  jyrevious  edition  is  appended. 


mandsoftheday.     The  illustrations 
are  up-to-date  in  every  particular. — 

Atncrican  Practiiioner  and  News. 


This  is  a  splendid  work,  clear  and 
succinct,  but  at  the  same  time  ex- 
haustive enough  to  meet  the   de- 

DWIGHT  (EDWIN  WELLiES).     AN   EPITOME   OF  MEDICAL 

JUIIISPRUDENCE.     12mo,   240  pages.     Cloth,   $1  net.     See  Lea's 
Series  of  Medical  Epitomes,  page   18. 

AN  EPITOME  OF  TOXICOLOGY.     See  Lea's  Series  of  Medical 

Epitomes,  page  18. 

ECKL.EY  (WILLIAM  T.).  A  GUIDE  TO  DISSECTION  OF  THE 
HUMAN  BODY.  Octavo,  400  pages,  220  illustrations  in  black  and 
colors.     Cloth,  $3.50  net. 


and  the  text  plain  and  concise.  We 
regard  it  as  a  most  excellent  book. 
Nashville  Journal  of  Medicine  and 
Surgery. 


An  exceedingly  useful  hand-book 
for  the  student,  prepared  to  be  used 
in  connection  with  the  most  popular 
text-books  of  the  day.  Gray  and 
Gerrish.    The  arrangement  is  good 

EOKLEY  (WILLIAM  T.).  REGIONAL  ANATOMY  OF  THE 
HEAD  AND  NECK.  Octavo,  240  pages,  with  36  engravings  and 
20  plates  in  black  and  colors.     Cloth,  $2.50,  neL 

A  most  excellent  work  of  especial  that  chapter.  The  engravings,  and 
interest  to  the  dentist.  It  is  seldom  I  especially  the  colored  plates,  are 
one  sees  a  book  so  well  arranged  and  I  fine  and  if  the  student  cannot  get  a 
so  concisely  written  as  this  one.  At  { correct  understanding  from  their 
the  end  of  each  chapter  quiz  ques-  j  study  it  must  certainly  be  his  own 
tions  are  given  covering  the  text  in  [fault. — The  Dental  Summary. 

EDES  (ROBERT  T.).  TEXT-BOOK  OF  THERAPEUTICS  AND 
MATERIA  MEDICA,  In  one  8vo.  volume  of  544  pages.  Cloth,  $3.50. 

EDIS  (ARTHUR  W.).  DISEASES  OF  WOMEN.  A  Manual  for 
Students  and  Practitioners.  In  one  handsome  Svo.  volume  of  576  pages, 
with  148  engravings.    Cloth,  $3. 

EGBERT  (SENECA).    A   MANUAL   OF  HYGIENE  AND  SANI- 
TATION.    New  (3rd)  and  revised  edition.     In   one    12mo.  volume 
of  467  pages,  with  86    illustrations.     Cloth,  $2.25,  net. 
A  concise,  comprehensive  manual,  ( lay  reader.     It  deals  with  personal 

alike  suitable  for  the  medical  stu-  I  hygiene  as  well  as  public  health. — 

dent,  sanitary  inspector  and  for  the  I  The  Sanitarian. 

ELLIS  (GEORGE  VINER).  DEMONSTRATIONS  IN  ANATOMY. 
Eighth  edition.  Octavo,  716  pages,  with  249  engravings.  Cloth, 
$4.25 ;  leather,  $5.25. 

EMMET  (THOMAS  ADDIS).  THE  PRINCIPLES  AND  PRAC- 
TICE OF  GYN./ECOLOGY.  Third  edition.  Octavo,  880  pages,  with 
150  original  engravings.     Cloth,  $5 ;  leather,  $6. 

ERICHSEN  (JOHN  E.).  THE  SCIENCE  AND  ART  OF  SUR- 
GERY. Eighth  edition.  In  two  large  octavo  volumes  containing 
2316  pages,  with  984  engravings.     Cloth,  $9 ;  leather,  $11. 

ESSIG  (CHARLES  J.).  PROSTHETIC  DENTISTRY.  Bee  American 
Text-Books  of  Dentistry,  page  2. 

ESSIG  (CHARLES  J.)  and  KOENIG  (AUGUSTUS).  DENTAL 
METALLURGY,  New  (5tli)  edition,  thoroughly  revised.  12mo, 
318  pages,  76  engravings.     Cloth,  $2.00,  net.     Just   ready. 


It  is  compendious,  concise  and  readi- 
ly intelligible,  giving  the  essentials 
of  its  subject  in  its  most  modern 
aspect. — Indiana  Medical  Journal. 


10     Lka  Brothers  A  Co.,  Philadelphia  and  New  York. 

EVANS  (DAVID  J.).    A  POCKET  TEXT-BOOK  OF  OBSTETRICS. 

in  one  handsome  12mo.  volume  of  409  pages,  with  148  illustrations. 
Cloth,  $1.75,  net;    limp  leather,  $2.25,  net.   Lea's  Series  of  Pocket 
Text-books,  edited  by  Bern  B.  Gallaudet,  M.D.  See  page  18. 
AVritten  for  the  medical  student 
and  practitioner  by  one  whose  ex- 
perience, both  clinical  and  teaching, 
has  specially  fitted  him  for  the  task. 

EWING  (JAMES).     CLINICAL  PATHOLOGY  OF  THE  BLOOD.   A 

Treatise  on   the    General    Principles    and    Special   Applications  of 

Hematology.      New  (2d)   edition,   thoroughly    revised.      Handsome 

octavo,  492  pages,  43  engravings,  18  colored  plates.     Cloth,  $3.50,  7iet. 

In  all  of  those  medical  colleges  in  !  certainly  made  it  a  reliable  guide 

which  hematology  is  taught  the  book  \  for  all  those  who  desire  to  enter  up- 

before  us  has  been  recommended  for  j  on  the  work  of  blood  examination. 

a  text-book,  and  no  better  one  could  j  — St    Louis   Medical   and  Surgical 

have  been  chosen.    The  author  has  1  Journal. 

EXAMINATION  SERIES  (STATE  BOARD).  See  page  26. 

FARQUHARSON  (ROBERT).  A  GUIDE  TO  THERAPEUTICS. 
Fourth  American  from  fourth  English  edition,  revised  by  Frank 
Woodbury,  M.  D.    In  one  12mo.  volume  of  581  pages.    Cloth,  $2.50. 

FERGUSON  (J.  B ).  AN  EPITOME  OF  NOSE  AND  THROAT 
DISEASES.     See  Lea's  Series  of  Medical  Epitomes,  page  18. 

FIELD  (GEORGE  P.).  A  MANUAL  OF  DISEASES  OF  THE 
EAR.  Fourth  edition.  In  one  octavo  volume  of  391  pages,  with  73 
engravings  and  21  colored  plates.      Cloth,  $3.75. 

FINDLEY   (PALMER  D.).      A  TREATISE  ON   GYNECOLOGI- 
CAL  DIAGNOSIS.     Octavo,  493  pages,  210  engravings,  45  plates, 
in  black  and  colors.     Cloth,  $4.50 ;  leather,  $5.50,  net. 
This  elaborate  work  will  occupy  i  and  will   be  found   of  the  greatest 
a    unicjue    place    in    gynecological    value  to  both.  It  is  thoroughly  illus- 
literature  inasmuch  as  it  is  the  first    trated    with    excellent     cuts     and 
on     the    subject    in     the     English    colored  engravings.     The  text  is  full 
language.     litis  adapted  to  the  needs    and   plain  — Nashville    Journal    of 
of   both   student  and    practitioner,  I  Medicine  and  Surgery. 

FLINT  (AUSTIN).  A  TREATISE  ON  THE  PRINCIPLES  AND 
PRACTICE  OF  MEDICINE.  Seventh  edition,  thoroughly  revised 
by  Frederick  P.  Henry,  M.  D.  In  one  large  8vo.  volume  of  1143 
pages,  with  engravings.     Cloth,  $5.00 ;  leather,  $6.00. 

FLINT  (AUSTIN).  A  PRACTICAL  TREATISE  ON  THE  DIAG- 
NOSIS AND  TREATMENT  OF  DISEASES  OF  THE  HEART. 
Second  edition  enlarged.    Inoneoctavo  volume  of  550  pages.    Cloth,  $4. 

ON  PHTHISIS :  ITS  MORBID  ANATOMY,  ETIOLOGY,  ETC. 

A  Series  of  Clinical  Lectures.      8vo.  442  pages.     Cloth,  $3.60. 
■ESSAYS  ON  CONSERVATIVE  MEDICINE  AND  KINDRED 


TOPICS.     12mo,  214  pages.     Cloth,  $1.38. 
FORMULARY,  POCKET.  See  page  32. 

FOSTER  (MICHAEL).    A  TEXT-BOOK  OF  PHYSIOLOGY.    Sixth 

and  revised  American  from  the  sixth  English  edition.     In  one  large 

octavo  volume  of  923  pp.,  with  257  illus.     Cloth,  $4.50 ;  leather,  $5.50. 

Unquestionably  the  best  book  that  j  busy  physician  it  can   scarcely   be 

can  be  placed  in  the  student's  hands,    excelled. — The  Phila.  Polyclinic. 

and  as  a  work  of  reference  for  the 


Lea  Brothers  &  Co.,  Philadelphia  and  New  York.     11 

FOTHERGBLL  (J.  MIL.NER).  THE  PRACTITIONER'S  HAND- 
BOOK OF  TREATMENT.  Third  edition.  In  one  handsome  octavo 
volume  of  664  pages.     Cloth,  $3.75 ;  leather,  $4.75. 

FOWNES  (GEORGE).  A  MANUAL  OF  ELEMENTARY  CHEM- 
ISTRY (INORGANIC  AND  ORGANIC).  Twelfth  edition.  Em- 
bodying  Watts'  Physical  and  Inorganic  Chemistry.  12mo.,  1061 
pages,  168  engravings,  and  1  colored  plate.    Cloth,  $2.75  ;  leather,  $3.25. 

FRANKIiAND  (E.)  AND  JAPP  (F.  R.).  INORGANIC  CHEMISTRY. 
In  one  handsome  octavo  volume  of  677  pages,  with  51  engravings  and 
2  plates.     Cloth,  $3.75 ;  leather,  $4.75. 

FULLER  (EUGENE).  DISORDERS  OF  THE  SEXUAL  OR- 
GANS IN  THE  MALE.  In  one  very  handsome  octavo  volume  of 
238  pages,  with  25  engravings  and  8  full-page  plates.     Cloth,  $2. 

GALLAUDET  (BERN  B.).  A  POCKET  TEXT-BOOK  ON  SUR- 
GERY. In  one  handsome  12mo.  volume  of  about  400  pages,  with  many 
illustrations.    Shortly.    See  Lea^s  Series  of  Pocket  Text-hooks,  page  18. 

GANT  (FREDERICK  JAMES).  THE  STUDENT'S  SURGERY.  A 
Multum  in  Parvo.  In  one  square  octavo  volume  of  845  pages,  with 
159  engravings.     Cloth,  $3.75. 

GAYLORD  (HARVEY  R.)  and  ASCHOFF  (LUDWIG).    THE 
PRINCIPLES  OF  PATHOLOGICAL  HISTOLOGY.    With  an  in- 
troductory note  by  William  H.  Welch,  M.  D.    Quarto,  364  pages, 
with  81  engravings  and  40  f nil-page  plates.     Cloth,  $7.50,  net. 
Admirably  arranged  and  beauti-  ;  tion  of  a  work  which  should  be  in 

fully  illustrated.    The  authors  are    the  hands  of  every  student  of  morbid 

to  be  congratulated  on  the  produc-  I  histology. — London  Practitioner. 

GERRISH  (FREDERIC  H.).    A    TEXT-BOOK   OF  ANATOMY. 
By  American  Authors,  Edited  by  Frederic  H.  Gerrish,  M.  D.    Second 
and  revised  edition.     In  one  imperial   octavo  volume  of  937  pages, 
with  1003  illustrations  in  black  and  colors.    Cloth,  $6.50,  net.  leather, 
$7.50,  net ;    half  Morocco.  $8.00,  net. 
The  illustrations  far  outnumber  ;      The  text  is  accurate,  concise,  and 
and  exceed  in  size  and  in  profusion  |  gives  the    essentials   of  descriptive 
of  colors  those  in  any  previous  work  ;  |  anatomy  with  less  waste  of  words  and 
and  they  can  well  claim  to  be  the  i  better  emphasis  of  important  points 
most  successful  series  of  anatomical  '  than   any    similar    text-book    with 
pictures  in  the  world. — The  Ameri-  i  which  we  are  familiar. — The  Boston 
can  Practitioner  and  News.  \  Medical  and  Surgical  Journal. 

GIBBES  (HENEAGE).  PRACTICAL  PATHOLOGY  AND  MORBID 
HISTOLOGY.  Octavo,  314  pages,  with  60  illustrations.   Cloth,  $2.75. 
GRAY    (HENRY).      ANATOMY,   DESCRIPTIVE    AND    SURGI- 
CAL.    New  (fifteenth)  edition  thoroughly  revised.     In  one  imperial 
octavo  volume  of  1249  pages,  with  780  large  and  elaborate  engrav- 
ings.    Price  with  illustrations  in  colors,  cloth,  $6.25,  net ;  leather, 
$7.25,   net.     Price,   with   illustrations    in   black,   cloth,   $5.50,  net; 
leather,$6.50,  net. 
This   is    the  best  single  volume    so  indefinitely.    No  book  will  ever 
upon    Anatomy     in     the     English  ;  take  its  place  before  the  Examining 
language. —  University  Medical  Mag-    Boards  of  this  country — it  will  be 
azine.  their     standard. — The       American 

Holds  first  place  in  the  esteem  of   Practitioner  and  News. 


both    teachers    and    students. — The 
Brooklyn  Medical  Journal. 

AVithout  a  doubt  the  most  com- 
plete work  on  anatomy  published 
in  the  English  language.  Gray  still 
remains  the  text-book  of  all  medical 
students,  and  will  doubtless  remain 


The  most  largely  used  anatomical 
text-book  published  in  the  English 
language. — Annals  of  Surgery. 

Gray's  Anatomy  affords  the  student 
more  satisfaction  than  any  other 
treatise  with  which  we  are  familiar. 
— Bi(ffalo  Med.  Journal. 


12      Lea  Bbothbbs  &  Co.,  Philadelphia  and  New  York. 


GRAYSON  (CHARLES  P.).  DISEASES  OF  THE  THROAT, 
NOSE.  AND  ASSOCIATED  AFFECTIONS  OF  THE  EAR.  In 
one  handsome  octavo  volume  of  548  pages,  with  129  engravings  and 
8  plates  in  colors  and  monochrome.     Cloth,  $3.50,  net. 

It  is  a  practical  book,  telling  i  and  it  is  projmrtiouately  valuable. 
"  not  only  what  to  do,  but  how  to  do  The  book  is  well  written  and  is  a 
it."  Under  "Treatment,"  the  author  serviceable  and  practical  addition  to 
is  very  evidently  and  sincerely  giv-  the  literature  of  the  sulyects  treated, 
ing,  not  compilations  from  other  — Medical  Record. 
men's  work,  but  his  own  experiences, 

GREEN  (T.  HENRY).    PATHOLOGY  AND  MORBID  ANATOMY. 

Ninth  edition.     In  one  handsome  octavo  volume  of  577  pages,  with 
339  engravings  and  4  colored  plates.     Cloth,  $3.25,  net. 

The  work  is  an  essential  to  the 


practitioner — whether  as  surgeon  or 
physician.     It  is  the  best  of  up-to- 


date  text-books. —  Virginia  Medical 
Monthly. 


GREENE  (WUiLIAM  H.).  A  MANUAL  OF  MEDICAL  CHEM- 
ISTRY. For  the  Use  of  Students.  Based  upon  Bowman's  Medical 
Chemistry.    In  one  12mo.  vol.  of  310  pages,  with  74  illus.   Cloth,  $1.75. 

GRINDON    (JOSEPH).      A    POCKET    TEXT-BOOK    OF    SKIN 

DISEASES.     In  one  handsome  12mo.  volume  of  367  pages,  with  39 

illustrations.       Cloth,  $2.00.  net;   flexible  leather,  $2.50,  net.      See 

Lea^s  Series  of  Pocket  Text-hooks,  page  18. 

A  compendious  and   trustworthy  !  tology.    As  a  therapeutic  adviser  for 

guide  book  for  the  practitioner  as  '  the  doctor  it  is  replete  with  direc- 

well    as    student,    embodying    the  ,  tions  and   valuable  formulae. — The 

most  recent  developments  in  derma-  1  Virginia  Medical  Semi-Monthly. 

GROSS  (SAMUEL  D.).  A  PRACTICAL  TREATISE  ON  THE  DIS- 
EASES, INJURIES  AND  MALFORMATIONS  OF  THE  URINARY 
BLADDER,  THE  PROSTATE  GLAND  AND  THE  URETHRA. 
Third  edition.    Octavo,  574  pages,  with  170  illustrations    Cloth,  $4.50. 

GUENTHER(A.  E.  AND  T.  C).    AN  EPITOME  OF  PHYSIOLOGY. 

12mo,  225  pages,  illustrated.    Cloth,  $1.00,  net.     Lea's  Series  of  Medi- 
cal Epitomes.     See  page  18. 

HABERSHON(S.  O.).  DISEASES  OF  THE  ABDOMEN.  Second 
American  from  the  third  English  edition.  Octavo,  554  pages,  with 
11  engravings.    Cloth,  .$3.50. 

HALE  (HENRY  E.).  AN  EPITOME  OF  ANATOMY.  12mo., 
389  pages,  71  engravings.  Cloth,  $1.00,  net.  See  Lea's  Series  of 
Medical  Epitomes,  page  18. 

HALL  (WINFIELD  S.).  TEXT- BOOK  OF  PHYSIOLOGY.  Octavo 
of  672  pages,  with  343  engravings,  and  6  full  page  colored  plates. 
Cloth,  $4.00,  net  ;   leather,  $5.00,  net. 


Students  and  teachers  may  pur- 
chase the  work  with  the  certainty 
that  they  will  obtain  a  thoroutrhiy 
sound  and  reliable  exposition  of  the 
present  state  of  phy.siological  know- 
ledge.— The  London  Lancet, 


The  clearness  with  which 
physiological  facts  are  demonstrated 
makes  it  of  special  value  to  the 
medical  student.  Western  Medical 
Review. 


Lea  Brothees  &  Co.,  Philadelphia  and  New  Yoek.     13 


HAMILTON  (ALLAN  MCLANE).  NERVOUS  DISEASES,  THEIR 
DESCRIPTION  AND  TREATMENT.  Second  and  revised  edition. 
In  one  octavo  volume  of  598  pages,  with  72  engravings.    Cloth,  $4. 

HAMILTON  (MILDRED).  A  POCKET  TEXT-BOOK  OF  MAS- 
SAC iE.     Preparing.     See  Lea's  Series  of  Pocket  Text-Books,  page  18. 

HARD  A  WAY  (W.  A.).  MANUAL  OF  SKIN  DISEASES.  Second 
edition.  In  one  12mo.  volume  of  560  pages,  with  40  illustrations  and 
2  plates.    Cloth,  $2.25,  net. 


The  best  of  all  the  small  books  to 
recommend  to  students  and  practi- 
tioners. Probably  no  one  of  our 
dermatologists  has  had  a  wider  every- 


day clinical  experience.  His  great 
strength  is  in  diagnosis,  descriptions 
of  lesions  and  especially  in  treat- 
ment.— Indiana  Medical  Journal. 


HARE  (HOB ART  AMORY).     PRACTICAL    DIAGNOSIS.    THE 

USE  OF  SYMPTOMS  IN  THE  DIAGNOSIS  OF  DISEASE.    Fifth 

edition.     In  one  octavo  volume  of  692  pages,  with  240  engravings 

and  25  full-page  colored   plates.     Cloth,  $5.00,  net ;    leather,  $6.00, 

net;   half  Morocco,  $6.50,  wei. 

Dr.  Hare  is  eminently  practical,  I  physical  signs    and    clinical   tests. 

he  appreciates  the  needs  of  the  gen-  i  This  makes  the  treatise  a  complete 

eral  practitioner ;  and  in  presenting  j  guide  for  the  purposes  of  diagnosis. 

the  symptoms  as  met  at  the  bedside    The  chemical  and  microscopical  ex- 

and  discussing  disease  as  it  actually  \  amination  of  the  blood  is  described 


in  detail.     Directions  as  to  urinary 
diagnosis  are  concise  and  complete. 

— St.  Louis  Courier  of  Medicine. 


appears,  he  has  no  peer.  The  new 
edition  has  been  carefully  revised, 
and  its  scope  has  been  widened  to  in- 
clude not  only  symptoms  but  also 

HARE  (HOBART  AMORY).  A  TEXT-BOOK  OF  PRACTICAL 
THERAPEUTICS,  with  Special  Reference  to  the  Application  of  Reme- 
dial Measures  to  Disease  and  their  Employment  upon  a  Rational 
Basis.  With  articles  on  various  subjects  by  well-known  specialists. 
Ninth  and  revised  edition.  In  one  octavo  volume  of  851  pages, 
with  105  engravings  and  4  colored  plates.  Cloth,  $4.00,  net;  leather, 
$5.00,  net;   half  Morocco,  $5.50, /i6<. 


•Just  the  book  the  active  physician 
most  needs.  He  generally  needs 
the  information  he  seeks  quickly, 
too,  and  here  he  finds  it,  accessible, 
clear  and  adequate.  ()n  every 
occasion  we  have  consulted  its  pages, 
and  tliey  are  many,  we  have  never 
turned  away  in'  disappointment. 
This  must  continue  to  be  the  text- 
book, par  excellence,  of  therapeutics. 
— Buffalo  Medical  Joxirnal. 

We  know  of  no  book  which  is  its 
equal  in  practical  therapeutics. — 
Boston  Medical  and  Surgical  Jour 
nal. 

The  great  value  of  the  work  lies 
in  the  fact  that  precise  indications 


for  administration  are  given.  A 
complete  index  of  diseases  and 
remedies  makes  it  an  easy  reference 
work.  It  has  been  arranged  so  that 
it  can  be  readily  used  in  connection 
with  Hare's  Practical  Diagnosis. 
For  the  needs  of  the  student  and 
general  practitioner  it  has  no  equal. 
— Medical  Sentinel. 

The  best  planned  therapeutic  work 
of  the  century. — Annerican  Prac' 
titioner  and  News. 

It  is  a  book  precisely  adapted  to 
the  needs  of  the  busy  practitioner, 
who  can  rely  upon  finding  exactly 
what  he  needs. — The  National  Med- 
ical Heview. 


HARE  (HOBART  AMORY)    ON  THE  MEDICAL   COMPLICA- 
TIONS AND   SEQUELS  OF  TYPHOID  FEVER.      Octavo,  276 
pages,  21  engravings   and  two  full-page  plates.     Cloth,  $2.40,  net. 
A  very  valuable  production.   One  j  read  with  great  profit. — Cleveland 

of  the  very  best   products  of   Dr.  I  Journal  of  Medicine. 

Hare  and  one  that  every  man  can  i 


14     Lka  Beothkbs  &  Co.,  Philadelphia  and  New  York. 


HARE:'S  system  of  practical  therapeutics.  In  a  series 
of  contributions  by  eminent  practitioners.  Second  edition.  In  three 
large  octavo  volumes  containing  2693  pages,  with  457  engravings 
and  26  full-page  plates.  Price  per  volume,  cloth,  $5,00;  leather, 
$6.00;  half  morocco,  $7.00.  Full  prospectus  free  on  application. 
For  sale  by  subscription  only. 


The  System  is  one  of  the  most  im 
portant  additions  a  busy  physician 
can  make  to  the  working  literature 
of  his  library. — Jiuffalo  Medical 
Journal. 

The  volumes  are  practical.  They 
reflect  the  editor's  appreciation  of 
modern  medicine.  The  third  vol- 
ume is  given  up  to  surgery  and  the 
specialties,  and  this  makes  the  set 
suitable  for  the  general  practitioner. 
— The  Boston  Medical  and  Surgical 
Journal. 

The    dominant    feature    of    the 


work,  one  that  the  well-known 
editor  constantly  presents,  is  the 
everyday  workability  of  treat- 
ments advocated.  Here  are  no 
lengthy  theoretical  dissertations 
largely  padded  by  quotations  from 
European  authors,  but  concise,  prac- 
tical rules  that  can  be  made  to  fit 
present-day  needs.  What,  why 
and  HOW  are  the  questions  with  ref- 
erence to  the  use  of  drugs  that  the 
authors  answer  —  particularly  the 
HOW. — Medical  News. 


HARRINGTON  (CHARLES).  PRACTICAL  HYGIENE.  Second 
edition.  Handsome  octavo,  755  pages,  113  engravings,  12  plates. 
Net,  $4.25. 

This  book  is  by  far  the  best  work-  j  at  the  same  time  is  perfectly  familiar 
ing  manual  of  practical  hygiene  that  I  with  allied  branches,  which  are  so 
has    yet    appeared   in   the  English    necessary  for  a  full  comprehension 


language.  The  subject  is  handled 
exceedingly  well,  and  shows  that  its 
author  is  a  practical  hygienist,  and 


of  the  broad  subject  treated.  It  is 
thoroughly  up  to  date. — Interstate 
Medical  Journal. 


HARTSHORNE  (HENRY).  A  CONSPECTUS  OF  THE  MEDI- 
CAL SCIENCES.  Comprising  Manuals  of  Anatomy,  Physiology, 
Chemistry,  Materia  Medica,  Practice  of  Medicine,  Surgery  and  Ob- 
stetrics. Second  edition.  In  one  royal  12mo.  vol.  of  1028  pages,  with 
477  illus.     Cloth,  $4.25 ;  leather,  $5. 

HAYDEN  (JAMES  R.).  A  POCKET  TEXT-BOOK  OF  VENER- 
EAL DISEASES.  Third  edition.  In  one  12mo.  volume  of  304 
pages,  with  66  engravings.  Cloth,  $1.75,  net.  Flexible  leather, 
$2.25,  nei.     See  Lea's  Series  of  Pocket  Text-Books,  page  18. 

The  volume  is  practical,  concise,  [  it  is  particularly  thorough. — Pacific 
definite  and  satisfactorily  full.     In  j  Medical  Journal. 
matters  of  diagnosis  and  treatment! 

HAYEM  (GEORGES)  AND  HARE  (H.  A.).  PHYSICAL  AND 
NATURAL  THERAPEUTICS.  The  Remedial  Use  of  Heat,  Elec- 
tricity, Modifications  of  Atmospheric  Pressure,  Climates  and  Mineral 
Waters.  Edited  by  Prof.  H.  A.  Hare,  M.D.  In  one  octavo  volume 
of  414  pages.with  113  engravings.     Cloth,  $3. 

HERMAN  (G.  ERNEST).    FIRST  LINES  IN  MIDWIFERY.    In 

one  12mo.  vol.  of  198  pages,  with  80  engravings.     Cloth,  $1.25.     See 
Student's  Series  of  Manuals,  page  27. 

HERMANN  (li.).  EXPERIMENTAL  PHARMACOLOGY.  A  Hand- 
book of  the  Methods  for  Determining  the  Physiological  Actions  of 
Drugs.  Translated  by  Robert  Meade  Smith,  M.  D.  In  one  12mo. 
Tolume  of  199  pages,  with  32  engravings.    Cloth,  $1.50. 


Lea  Brothees  &  Co.,  Philadelphia  and  New  York.     16 


HE^RRICK  (JAMES  B.).    A  HANDBOOK  OF  DIAGNOSIS.    In 

one  handsome  12mo,  volume  of  429  pages,  with  80  engravings  and  2 
colored  plates.     Cloth,  $2.50. 


We  commend  the  book  not  only  to 
the  undergraduate,  but  also  to  the 
physician  who  desires  a  ready  means 
of  refreshing  his  knowledge  of  diag- 
nosis in  the  exigencies  of  professional 
life. — Memphis  3Iedical  Monthly. 


Excellently  arranged,  practical, 
concise,  up-to-date,  and  eminently 
well  fitted  for  the  use  of  the  prac- 
titioner as  well  as  of  the  student. — 
Chicago  Med.  Recorder. 


HERTER   (C.   A.).     LECTURES  ON  CHEMICAL  PATHOLOGY, 

In  one  12mo.,  volume  of  454  pages.     Cloth,  $1.75,  net. 


The  lectures  are  eminently  prac- 
tical. A  great  variety  of  subjects 
is  dealt  with  in  a  most  attractive 
manner.  The  volume  is  not  a  de- 
scription of  the  normal  physiological 
processes  going  on  in  the  healthy 


body,  but  rather  an  account  of  the 
altered  chemical  changes  which  take 
place  in  the  different  organs  and  se- 
cretions in  various  diseases.  The 
book  is  full  of  interesting,  practical 
points.— Jo/) «.s  Hopkins  Bulletin. 


Hllili  (BERKELEY).  SYPHILIS  AND  LOCAL  CONTAGIOUS 
DISORDERS.    In  one  8vo.  volume  of  479  pages.    Cloth,  $3.25. 

HIIjIjIER  (THOMAS).  A  HANDBOOK  OF  SKIN  DISEASES. 
Second  edition.  In  one  royal  12mo.  volume  of  353  pages,  with  two 
plates.    Cloth,  $2.26. 

HIRST  (BARTON  C.)  AND  PEERSOL  (GEORGE  A.).  HUMAN 

MONSTROSITIES.  Magnificent  folio,  containing  220  pages  of  text 
and  illustrated  with  123  engravmgs  and  39  large  photographic  plates 
from  nature.   In  four  parts,  price  each,  $5. 


HOBL.YN  (RICHARD  D.).  A  DICTIONARY  OF  THE  TERMS 
USED  IN  MEDICINE  AND  THE  COLLATERAL  SCIENCES. 
Thirteenth  edition.  In  one  12mo.  volume  of  845  pages.  Cloth, 
$3.00,  net. 


This  is  a  volume  of  almost  900 
pages,  printed  in  easily-read  type, 
and  is  fully  up  to  date,  embracing, 
practically  all  the  terms.    The  fact 


that  it  has  gone  through  12  editions 
is  an  evidence  that  the  medical  pro- 
fession has  found  it  meets  their 
wants. — Canada  Medical  Record. 


HOLIilS  (A.  W.).  AN  EPITOME  OF  MEDICAL  DIAGNOSIS. 

Lea^s  Series  of  Medical  Epitomes,  page  18. 


See 


HOLMES  (TIMOTHY).  A  TREATISE  ON  SURGERY.  Its  Prin- 
ciples and  Practice.  Fifth  edition.  Edited  by  T.  Pickering  Pick, 
F.R.C.S.  In  one  handsome  octavo  volume  of  1008  pages,  with  428  en- 
gravings.    Cloth,  $6.00 ;  leather,  $7.00. 


HOLMES  (TIMOTHY).  A  SYSTEM  OF  SURGERY.  With  notes  and 
additions  by  various  American  authors.  Edited  by  John  H.  Packard, 
M.D.  In  three  8vo.  volumes  containing  3137  pages,  with  979  engravings 
and  13  plates.    Per  volume,  cloth,  $6.00  ;  leather,  $7.00. 


l6     Lea  BROTHftBS  &  Co.,  pHiLAt)B:Li»ttiA  and  New  York. 


HUNTINGTON  (GEORGE  S.).  A  TREATISE  ON  ABDOMINAL 
ANATOMY.  Quarto,  590  pages  including  300  full-page  plates  in 
black  and  colors,  containing  582  figures.  De  luxe  binding,  $10,  net. 
The  mysteries  of  the  Peritoneum  and  Abdominal  Cavity  particularly 
concern  anatomists,  surgeons,  gynecologists  and  obstetricians,  and  in- 
terest the  general  practitioner  to  a  degree  scarcely  less.  This  compre- 
hensive and  authoritative  work  will  therefore  appeal  to  an  unusually 
wide  constituency  of  readers.  Dr.  Huntington  has  approached  the  sub- 
ject in  the  light  tbrown  upon  it  by  embryology  and  comparative  anatomy, 
thereby  clarifying  the  hitherto  difficult  and  complicated  morphological 
prol)lems  presented  by  these  regions.  The  book  is  uniijue  in  its  marvelous 
wealth  of  illusti-ations,  amounting  practically  to  an  Atlas,  with  full  ex- 
planatory text.  The  structural  details  of  the  Human  Caecum  and 
Appendix  are  considered  very  fully  by  reason  of  the  extensive  material 
available  and  the  paramount  clinical   importance  of  these  subjects. 

HYDE  (JAMES  NEVINS)  AND  MONTGOMERY  (F.  H.)  A 
PRACTICAL  TREATISE  ON  DISEASES  OF  THE  SKIN.  Sixth 
edition,  thoroughly  revised.  Octavo,  832  pages,  with  107  engrav- 
ings and  27  full-page  plates,  9  of  which  are  colored.  Cloth,  $4.50,  net; 
leather,  $5.60, 7iet;  half  Morocco,  $6.00,  net. 


This  is  beyond  doubt  the  most 
successful  work  on  skin  diseases. 
This  work  is  now  looked  upon  as 
the  American  authority. — St.  Louis 
Medical  and  Surgical  Journal. 

The  first  American  text-book. — 
Northwestern  Lancet. 

The  work  answers  the  needs  of  the 
general  practitioner,  the  specialist, 
and  the  student. — The  Ohio  Med- 
ical Journal. 

A  treatise  of  exceptional  merit 
characterized  by  conscientious  care 
and  scientific  accuracy.  —  Buffalo 
Medical  and  Surgical  Journal. 

JACKSON  (GEORGE  THOMAS). 

HANDBOOK  OF  DISEASES  OF 


A  complete  exposition  of  our 
knowledge  of  cutaneous  medicine  as 
it  exists  to-day.  The  teaching  in- 
culcated throughout  is  sound  as  well 
as  practical. — The  American  Jour- 
nal of  the  Medical  Sciences. 

It  is  the  best  one-volume  work 
that  we  know. —  Virginia  3Iedical 
Semi- Monthly. 

A  full  and  thoroughly  modern 
text-book  on  dermatology.  —  The 
Pittsburg  Medical  Review. 

The  most  practical  handbook  on 
dermatology  with  which  we  are  ac- 
quainted.— Chicago  Med.  Recorder. 

THE   READY-REFERENCE 
THE    SKIN.     Fourth  edition. 


In  one  12mo.  volume  of  617  pages,  with  82  illustrations  and  3  colored 
plates.    Cloth,  $2.75,  net. 


The  work  is  especially  rich  in 
formuhe  and  practical  methods  of 
treatment. — Medicine. 


Without  doubt  forms  one  of  the 
best  guides  for  the  beginner  in  der- 
matology that  is  to  be  found  in  the 
English  language. — Medicine. 

JAMIESON  (W.  AL.L.AN).  DISEASES  OF  THE  SKIN.  Third 
edition.  In  one  octavo  volume  of  656  pages,  with  1  engraving  and  9 
double-page  chromo-lithographic  plates.    Cloth,  $6. 

JEWETT    (CHARLES).      THE    PRACTICE    OF   OBSTETRICS. 

By  American  Authors.  Second  edition.  Octavo,  775  pages,  with 
445  engravings  in  black  and  colors,  and  35  full-page  colored 
plates.  Cloth,  $5.00,  net ;  leather,  $6.00,  net;  half  Morocco,  $6.50,  net. 


The  most  complete  of  the  recent 
obstetric  text-books  The  illustra- 
tions are  superb  and  possess  the  merit 
of  clearness  and  accuracy. — Buffalo 
Medical  and  Surgical  Jo^irnal. 

It  is  pre-eminently  a  practical 
treatise  suited  to  the  needs  of  medical 
classes,  while,  at  the  same  time,  it 


furnishes  a  concise,  comprehensive 
and  trustworthy  guide  to  the  prac- 
titioner. We  regard  this  as  being 
one  of  the  most  scientific  and 
thoroughly  modern  treatises  upon 
this  important  subject  in  use  to-day. 
— Ajner.  Gynecological  and  Obstet- 
rical Journal. 


Lea  Brothers  &  Co.,  Philadelphia  and  New  York.     17 


JEWETT  (CHARIjES).  ESSENTIALS  OF  OBSTETRICS.    Second 
edition.     In  one  12mo.  volume  of  385  pages,  with  80  engravings  and 
5  colored  plates.     Cloth,  $2.25,  net. 
This  is  the  best  epitome  of  obstet-  |  students  and  practitioners  and  to  lec- 


rics  with  which  we  are  familiar.  It 
is  sutftciently  illustrated  to  make 
clear  its  text.  Its  contents  are  well 
selected.    It  can  be  recommended  to 


turers  who  need  to  review  salient 
points  of  obstetrics  in  preparing  their 
instruction. — The  American  Journal 
of  the  Medical  Sciences. 


JUL.ER  (HENRY).  A  HANDBOOK  OF  OPHTHALMIC  SCIENCE 
AND  PRACTICE.  New  (3rd)  edition.  In  one  octavo  volume  of  733  pp., 
with  190  engravings,  25  chromo-lithographic  plates.    Cloth,  .^5.25, 7iet. 

KELL.Y  (A.  O.  J.).  A  MANUAL  OF  THE  PRACTICE  OF  MEDI- 
CINE.   Octavo,  about  600  pages,  illustrated.    Preparing. 

KIEPE  (EDWARD  J.).  AN  EPITOME  OF  MATERIA  MEDICA 
AND  THERAPEUTICS.  See  Lea's  Series  of  Medical  Epitomes,  p.  18. 

KING  (A.  F.  A.).  A  MANUAL  OF  OBSTETRICS.  New  (9th)  edition.  In 
one  12mo.  volume  of  629  pages,  with  275  illustrations.    Cloth,  $2.50,  net. 


The  most  succinct,  reliable  and  at 
the  same  time  individual  book  for  a 
student  or  practitioner. — Medical 
News. 


The  best  manual  that  has  ever  been 
offered  to  us.  It  has  a  wonderful 
fund  of  information  in  a  very  small 
space. — N .  O.  Med.  and  Surg.  Jour. 
KIRK  (EDWARD  C).  OPERATIVE  DENTISTRY.  See  Amvn- 
can  Text-Books  of  Dentistry,  page  2. 

KliEIN  (E.).      ELEMENTS    OF  HISTOLOGY.     Fifih  edition.     In 
one  12mo.  volume  of  506  pages,  with  296  engravings.     Cloth,  $2.00, 
net.     See  Student's  Series  of  Manuals,  page  27. 
It  is  the  most  complete  and  con-  j      This  work  deservedly  occupies  a 
cise  work  of  the  kind  that  has  yet  i  first  place  as  a  text- book  on   his- 
emanated  from  the  press. — Med.  Age.  \  tology. — Canadian  Practitioner. 
KOPIilK    (HENRY).       THE    DISEASES    OF    INFANCY    AND 
CHILDHOOD.      Octavo,  675   pages  with   169  engravings,  and  32 
plates  in  black  and  colors.     Cloth,  $5.00,  net ;   leather,  $6.00,  net. 
Certainly  the   best  book  for  stu-  !  with  the  treatment,   which   is   not 
dents  we  have  seen  for  some  time,  as  j  complex,  but    simple  and  positive, 
it  is  clear,  concise,  epigrammatic  and  j  with    proper    regard   to  dosage,   so 
certain  to  make  an  impression  on  I  often  neglected  in  books  of  this  kind, 
the  mind  of  the  reader.    It  is  fully  \  to  the  detriment  of  the  student. — 
up  to  date.    We  are  specially  pleased  I  Chicago  Medical  Record. 
LANDIS  (HENRY  G.).  THE  MANAGEMENT  OF  LABOR.  In  one 

handsome  12mo.  volume  of  329  pages,  with  28  illus.   Cloth,  $1.75. 
liEA  (HENRY  C).    A  HISTORY  OF  AURICULAR  CONFESSION 
AND   INDULGENCES   IN   THE   LATIN    CHURCH.      In  three 
octavo  volumes  of  about  500  pages  each.     Per  volume,  cloth,  $3.00. 

CHAPTERS  FROM  THE  RELIGIOUS  HISTORY  OF  SPAIN ; 

CENSORSHIP  OF  THE  PRESS;    MYSTICS  AND  ILLUMINA- 
TI   OF   THE   ENDEMONIADAS;    EL  SANTO  NifJO   DE  LA 
GUARDIA.     12mo.,  522  pages.     Cloth,  $2  50. 
THE  MORISCOS  OF  SPAIN,  THEIR  CONVERSION  AND  EX- 
PULSION. In  one  royal  12mo.  volume  of  425  pages.  Cloth,  $2.25,  net. 

SUPERSTITION  AND  FORCE ;  ESSAYS  ON  THE  WAGER 

OF  LAW,  THE  WAGER  OF  BATTLE,  THE  ORDEAL  AND 
TORTURE.  Fourth  edition,  thoroughly  revised.  In  one  hand- 
some royal  12mo.  volume  of  629  pages.     Cloth,  $2.75. 

STUDIES  IN  CHURCH  HISTORY.    The  Rise  of  the  Temporal 

Power — Benefit  of  Clergy — Excommunication.  New  edition.  In  one 
handsome  12mo.  volume  of  605  pages.    Cloth,  $2.60. 


18     Lea  Brothers  &  Co.,  Philadelphia  and  New  York. 


LEA'S  SERIES  OF  MEDICAL.  EPITOMES.  Edited  by  Victor 
C.  Pedersen,  M.D.  Covering  the  entire  field  of  medicine  and  sur- 
gery in  twenty-two  convenient  volumes  of  about  250  pages  each, 
amply  illustrated  and  written  by  prominent  teachers  and  specialists. 
Compendious,  authoritative  and  modern.  Following  each  chapter 
is  a  series  of  questions  which  will  be  found  convenient  in  quizzing. 
Price  per  volume,  cloth,  $1,  net.  The  following  volumes  are  now  ready: 
Hale's  Anatomy.  Guentheks'  Physsiology.  McGlannax's  Phys- 
ics and  Inorganic  Chemistry.  McGlannax's  Organic  and  Phys- 
iological Chemistry.  Nag  el's  Nervous  and  Mental  Diseas'es. 
Wathen's  Histology.  Arohinard's  Bacteriology  and  Microscopy, 
Magee  &  Johnson's  Surgery.  AlliN(;  and  Grikfen  on  tlie  Eye 
and  Ear.  Schmidt's  Genito-Urinary  and  Venereal  Diseases. 
SCHALEK's  Dermatology.  Mantox's  Obstetrics.  Tuley's  Pedi- 
atrics. Dwight's  Jurisprudence.  Dwight's  Toxicology. 
The  following  volumes  are  in  press:  Kiei'E's  Materia  Medica  and 
Therapeutics.  Dayton's  Practice  of  Medicine.  Hollis'  Medical 
Diagnosis.  Arneill's  Clinical  Diagnosis  and  Urinalysis.  Sten- 
HOUSE's  Pathology.  Ferguson  on  the  Nose  and  Throat.  Pedersen 
and  Parker's  Gynecology. 

liEA'S  SERIES  OF  POCKET  TEXT-BOOKS,  edited  by  Bern 
B.  Gallaudet,  M.  D.  Covering  the  entire  field  of  Medicine  in  a 
series  of  18  very  handsome  12mo.  volumes  of  350-525  pages  each, 
profusely  illustrated.  Compendious,  clear,  trustworthy  and  modern. 
The  following  volumes  are  now  ready  : 

Ro('KWEll's  Anatomy.  Collins  and  Rockwell's  Physiology. 
Martin  and  Rockwell's  Chemistry  and  Physics.  Nichols  and 
Vale's  Histology  and  Pathology.  Schleif's  Materia  Medica,  Thera- 
peutics, Medical  Latin,  etc.  Malsbary's  Practice  of  Medicine. 
Potts'  Nervous  and  Mental  Diseases.  Hayden's  Venere*l  Diseases. 
Grindon's  Dermatology.  Ballenger  and  Wippern's  Diseases  of 
the  Eye,  Ear,  Throat  and  Nose.  Evans'  Obstetrics.  Crockett's 
Gynecology.  Tuttle's  Diseases  of  Children.  Zapffe's  Bacteriology. 
The  following  volumes  are  in  press  :  Collins  and  Davis'  Diagnosis  ; 
Gallaudet's  Surgery ;  Wicks' Nursing  and  Hamilton's  Massage. 
For  prices  and  separate  notices  see  under  various  authors'  names. 

LE  FEVRE  (EGBERT).    A  TEXT-BOOK  OF  PHYSICAL  DIAG- 
NOSIS.    In  one  12mo.  volume  of  450  pages, with  74  engravings  and 
12  plates.     Cloth,  $2.25,  net. 
This  book  will  take  front  rank,    tailed  attention,  and  the  same  meth- 
It  is  prepared  by  a  teacher  of  ex-    ods  as  applied  to  the  thorax  are  em- 
perience  and  a  clinician  of  accom-    ployed  and  explained  with  the  varia- 
plishment.    Le  Fevre  gives  adequate    tions  necessary.     A   numl)er  of  en- 
instruction  upon  all  the  details  of  j  gravings  and  X-ray  plates  elucidate 
diagnosis.    The  abdomen  receives  de-  I  the  text. — Buffalo  Medical  Journal. 

LONG  (ELI  H.).    A  MANUAL  OF  DENTAL  MATERIA  MEDICA 
AND  THERAPEUTICS.     12mo,  321  pages,  with  6  engravings  and 
18  plates.     Cloth,  $3.(i0,  net. 
The  author's  aim  has  been  to  cover  what  is  essential ;  to  treat  fully  all 
remedies  that  belong  properly  to  the  special  field  of  dental  medicine ;  to 
discuss  briefly  the  action  and  application  of  the  most  important  general 
remedies,  emphasizing  those  of  which  the  action  may  avail  in  dental  dis- 
eases and  emergencies,  and  to  furnish  matter  for  reference  that  will  cover 
all  ordinary  demands  of  the  dental  student  and  practitioner  as  to  general 
remedies,  their  preparations,  doses  and  uses.    The  value  of  the  work  is 
much   enhanced    by  the    extensive   Index    of   Drugs,   including    every 
drug  of  local  or  general  use  that  the  dentist  may  have  occasion  to  refer 
to.    This  index  is,  in  fact,  a  general  therapeutic  referendum  for  the  den- 
tal practitioner. 


Lea  Brothers  &  Co.,  Philadelphia  and  New  York.     19 


liOOMIS  (AliFRED  li.)  AND  THOMPSON  (W.  GILiMAN), 
EDITORS.  A  SYSTEM  OF  PKACTICAL  MEDICINE.  In 
Contributions  by  Various  American  Authors.  In  four  octavo  vol- 
umes of  about  900  pages  each,  fully  illustrated  in  black  and  colors. 
Per  volume,  cloth,  $5.00, 7icf ;  leather,  $6.00,  net ;  half  morocco,  $7.00, 
net.  For  sale  by  subscription  only.  Full  prospectus  free  on  applica- 
tion to  the  Publishers. 

LYMAN  (HENRY  M.).    THE  PRACTICE  OF  MEDICINE.    In  one 

very   handsome  octavo  volume  of  925  pages,  with  170  engravings. 
Cloth,  $4.75  ;  leather,  $6.75. 

McGLANNAN  (A.).  AN  EPITOME  OF  PHYSICS  AND  INOR- 
GANIC CHEMISTRY.     12mo.,  216  pages,  illustrated.    Cloth,  $1.00, 

net.     See  Lea's  Series  of  Medical  Epitomes,  page  18. 

AN  EPITOME  OF  OR(^{ANIC  AND  PHYSIOLOCJICAL  CHEM- 
ISTRY. 12mo.,  246  pages,  illustrated.  Cloth,  $1,  net.  See  Lea's 
Series  of  Medical  Epitomes,  pa,i(e  18. 

MAGEE  (M.  D.)  and  JOHNSON  (WALIiACE).  AN  EPITOME 
OF  SURGERY.  12mo.,  about  300  pages,  with  130  engravings. 
Cloth,  $1,  net.    Shorthj.    See  Jjea's  Series  of  Medical  Epitomes,  page  18. 

MAISCH  (JOHN  M.).  A  MANUAL  OF  ORGANIC  MATERIA 
MEDICA.  Seventh  edition,  thoroughly  revised  by  H.  C.  C.  Maisch, 
Ph.  G.,  Ph.  D.  In  one  very  handsome  12mo.  volume  of  512  pages,  with 
285  engravings.     Cloth,  $2.50,  net. 


The  best  handbook  upon  phar- 
macognosy of  any  published  in  this 
country. — Boston  Med.  &  Sur.  Jour. 


Used  as  text-book  in  every  college 
of  pharmacy  in  the  United  States 
and  recommended  in  medical  col- 
leges.— American  Therapist. 

MAL.SBARY    (GEORGE    E.).      A    POCKET    TEXT-BOOK    OF 
THEORY  AND  PRACTICE  OF  MEDICINE.     In  one  handsome 
12mo.  volume  of  405  pages,  with  45  illustrations.     Cloth,  $1.75,  net; 
flexible   red  leather,   $2.25,   net.       See  Lea's  Series  of  Pocket   Text- 
books,   page  18. 
Will  readily  commend  itself  to    recent  advances   in   medicine  with 
students    and    busy    practitioners,    the   best  of  that  which  is  old.  — 
bringing  forward  as  it  does  the  most    Medical  Review  of  Eevieivs. 

MANTON  (W.  P.).  AN  EPITOME  OF  OBSTETRICS,  12mo,  205 
pages,  82  illustrations.  Cloth,  $1.00,  nef.  ^ee  Lea's  Series  of  Medi- 
cal Epitomes,  page  18. 

MARSH  (HOWARD).  DISEASES  OF  THE  JOINTS.  In  one  12mo. 
volume  of  468  pages,  with  64  engravings  and  a  colored  plate.  Cloth,  $2. 
See  Series  of  Clinical  Manuals,  page  25. 

MARTIN  (EDWARD).  A  MANUAL  OF  SURGICAL  DIAGNOSIS. 
In  one  12mo.  volume  of  about  400  pp.,  fully  illustrated.      Preparing^ 

MARTIN  (WALTON)  AND  ROCKWELL  (W^M.  H.).  A  POCKET 
TEXT-BOOK  OF  CHEMISTRY  AND  PHYSICS.  In  one  hand- 
some 12mo.  volume  of  366  pages,  with  137  illustrations.  Cloth,  $1.50, 
net;    limp  leather,  $2.00,    net.        See  Lea's  Series  of  Pocket   Text- 


books, page  18, 
The  work  accurately  reflects  both 
sciences  in   their  present    develop- 
ment.   The  arrangement  of  the  mat- 


ter is  excellent. — The  Medical  and 
Surgical  Monitor. 


20     Lea  Brothees  &  Co.,  Philadelphia  and  New  Yobk. 


MEDICAL    EPITOME    SERIES.      See    Lea's    Series    of    Medical 
Epitomes,  page  18. 

MEDICAL.  NEWS  POCKET  FORMULARY,  see  page  32. 


MITCHELL  (S.  WEIR).  CLINICAL  LESSONS  ON  NERVOUS 
DISEASES.  In  one  12mo.  volume  of  299  pages,  with  19  engravings 
and  2  colored  plates.     Cloth,  $2.50. 


The  book  treats  of  hysteria,  recur- 
rent melancholia,  disorders  of  sleep, 
choreic  movements,  false  sensations 
of  cold,  ataxia,  hemiplegic  pain, 
treatment  of  sciatica,  erythromelal- 
gia,  reflex  ocularneurosis,  hysteric 


contractions,  rotary  movements  in 
the  feeble  miuded,  etc.  Few  can 
speak  with  more  authority  than  the 
author. —  The  Journal  of  the  Ameri- 
can Medical  Association. 


MITCHELL  (JOHN  K.).  REMOTE  CONSEQUENCES  OF 
INJURIES  OF  NERVES  AND  THEIR  TREATMENT.  In 
one  handsome  12mo.  volume  of  239  pages,  with  12  illustrations. 
Cloth,  $1.75. 

3IORROW  (PRINCE  A.).    SOCIAL  DISEASES  AND  MARRIAGE. 

SOCIAL  PROPHYLAXIS.    Octavo,  390  pages.    Cloth  $3.00,  net. 

Just  ready. 
This  subject  has  not  jireviously  ]  diseases  which  have  been  introduced 
been  written  upon  in  the  English  into  the  family  life,  and  there  are  no 
language,  and  although  we  are  quite  more  disiressingtragedies  than  those 
familiar  with  the  work  of  several  j  which  follow.  Morrow  discusses 
French  and  German  writers  on  the  every  possible  phase  of  the  subject, 
relationship  of  syphilis  and  gon- 1  and  he  has  made  many  timely  sug- 
orrhoja  to  marriage,  we  have  nowhere  eestions  which  are  both  helpful  and 
seen  a  more  masterly  presentation  of  hopeful.  This  book  should  be  read 
this  most  important  subject.  There  by  every  physician,  and  there  are  a 
is  probably  no  medical  practitioner  large  number  of  non-medical  readers 
who  does  not  frequently  have  occa-  j  who  might  read  it  with  profit. — St. 
sion  to  see  the  ravages  of  venereal  1  Paid  Medical  Journal. 


MUSSER  (JOHN  H.).  A  PRACTICAL  TREATISE  ON  MEDICAL 
DIAGNOSIS,  for  Students  and  Physicians.  New  (5th)  edition,  thor- 
oughly revised.  In  one  octavo  volume  of  1205  pages,  with  395  en- 
gravings and  63  full-page  colored  plates.  Cloth,  $6.50,  7iet ;  leather, 
$7.50,  net;  half  Morocco,  $8.00,  net. 
A  few  notices  of  the  previons  edition  are  appended : 

This  is  the  best  book  on  medical 
diagnosis  published  in  the  English 
language.  In  it  is  found  everything 
relating  to  the  proper  making  of  a 
correct  diagnosis.  It  is  complete, 
practical,  up-to-date, well  illustrated, 
well  arranged,  easy  for  reference, 
and  is  the  best  book  on  medical  diag- 
nosis, both  for  medical  students  and 
for  practitioners. — Maryland  Med- 
ical Journal. 


Medical  Diagnosis  has 
become  the  leading  and  standard 
work  on  its  subject.  In  this  work 
every  accepted  method  of  clinical 
and  bedside  investigation  is  de- 
scribed clearly  and  fully,  and  every 
effort  is  made  to  render  the  teachings 
of  the  book  of  such  practical  nature 
as  to  be  readily  available  to  the 
practitioner. — M  em  phis  Medical 
Monthly. 


NAGEL  (J.  D.).  AN  EPITOME  OF  NERVOUS  AND  MENTAL 
DISEASES.  12mo.,  about  250  pages,  illustrated.  Cloth,  .$1,  net. 
See  Lea's  Series  of  Medical  Epitomes,  page  18. 


Lea  Brothers  &  Co.,  Philadelphia  and  New  York.     21 

NATIONAJL  DISPENSATORY.  See  StUU,  Maisch  &  QupaH,  p.  27. 

NATIONAL  FORMULARY.  See  Stim,  Maisch  &  Ca^ari' 8  National 
Dispensatory,  page  27. 

NATIONAL  MEDICAL  DICTIONARY.    See  Billings,  page  4. 

NETTLE8HIP  (E.).  DISEASES  OF  THE  EYE.  Sixth  edition, 
thoroughly  revised.  In  one  12mo.  volume  of  562  pages,  with  192 
engravings,  and  5  colored  plates,  test-types,  formulae  and  color- 
blindness test.     Cloth,  $2.25,  net. 

This  work  for  compactness,  practi-  [      By  far  the  best  student's  text-book 
cality  and  clearness  has  no  superior  j  on  the  subject  of  ophthalmology. — 
in  the  English  language. — Journal  \  The  Clinical  Review, 
of  Medicine  and  Science.  I 

NICHOLS  (JOHN  B.)  AND  VALE  (F.  P.).  A  POCKET  TEXT- 
BOOK  OF  HISTOLOGY  AND  PATHOLOGY.  In  one  handsome 
l2mo.  volume  of  452  pages,  with  213  illustrations.  Cloth,  $1.75,  net : 
flexible  leather,  $2.25,  net.  See  Lea's  Series  of  Pocket  Text-books, 
page  18. 

Systematically  arranged,  and  in  !  can  safely  and  conscientiously  rec 
the  highest  degree  interesting,  ommend  it  to  both  students  and 
Thoroughly  up  to  date.  The  book  practitioners. —  The  St.  Louis  Medi- 
is  an  exceptionally  good  one.     We    cal  and  Surgical  Journal. 

NORRIS  (WM.  F.)  AND  OLIVER  (CHAS.  A.).  TEXT-BOOK  OF 

OPHTHALMOLOGY.    In  one  octavo  volume  of  641  pages,  with  357 
engravings  and  5  colored  plates.    Cloth,  $5  ;  leather,  $6. 

It  is  practical  in   its  teachings.  [  has  ever  been  offered  to  the  Amer- 
We  unreservedly  endorse  it  as  the    ican    medical    public. — Annals    of 
best,  the  safest  and  the  most  compre-    Ophthalmology  and  Otology. 
hensive  volume  upon  the  subject  that  j 

OVTEN    (EDMUND).      SURGICAL    DISEASES    OF    CHILDREN. 

In  one  12mo.  volume  of  525  pages,  with  85  engravings  and  4  colored 
plates.     Cloth,  $2.     See  Series  of  Clinical  Manuals,  page  25. 

PARK  (ROSWELL\  KDITOR.  A  TREATISE  ON  SURGERY 
BY  AMERICAN  AUTHORS.  Third  edition.  In  one  royal  octavo 
volume  of  1408  pages,  with  692  engravings  and  64  full-page  plates. 
Cloth,  $7.00,  net ;  leather,  $8.00,  net.  ^^T^Published  also  in  2  vol- 
umes. Vol.  I,  General  Surgery  and^  Surgical  Pathology.  Cloth, 
$3.75,  net.  Vol.  II,  Special,  Regional  and  Operative  Surgei-y. 
Cloth,  3.75,  net. 

The  work  is  fresh,  clear  and  practi- 
cal, covering  the  ground  thoroughly 
yet  briefly,  and  well  arranged  for 
rapid  reference,  so  that  it  will  be  of 
special  value  to  the  student  and  busy 
practitioner.  The  pathology  is 
broad,  clear  and  scientific,  while  the 
suggestions     upon     treatment     are 


clear-cut,  thoroughly  modern  and 
admirably  resourceful. — Johns  Hop- 
kins Hospital  Bulletin. 

The  latest  and  best  work  written 
upon  the  science  and  art  of  surgery. 
Columbus  Medical  Journal. 

It  is  thoroughly  practical  and  yet 
thoroughly  scientific. — Med.  News. 


22     Lka  Brothkbs  &  Co.,  Philadelphia  and  New  York. 


PARK  (WIL.L.IAM  H.).     BACTERIOLOGY  IN  MEDICINE  AND 

SURGERY.     12mo.,  688  pages,  with  87  illustrations  in   black  and 
colors,  and  2  plates.     Cloth,  $3.00  net. 


This  book  fills  a  very  distinct 
gap.  None  of  the  text-books  in  our 
language  take  up  the  subject  of  bac- 
teriology so  thoroughly  and  so 
soundly  as  does  this  from  the  point 


of  view  of  the  hygienist  and  public 
health  officer.  The  work  is  correct 
and  very  well  up  to  date, — The  Mon- 
treal Medical  Journal. 


PEDERSEN  (V.  C).  AND  PARKER  (E.  O.).    AN  EPITOME  OF 

GYNECOLOGY.     See  Lea's  Series  of  Medical  Epitomes,  page  18. 

PEPPER  (A.  J.).  SURGICAL  PATHOLOGY.  In  one  12mo.  volume 
of  511  pages,  with  81  engravings.  Cloth,  $2.  See  Student's  Series  of 
Manuals,  p.  27. 

PICK  (T.  PICKERING).      FRACTURES  AND  DISLOCATIONS. 

In  one  12mo.  volume  of  530  pages,  with  93  engravings.  Cloth,  $2. 
See  Series  of  Clinical  Manuals,  page  25. 

pijAyfalr  (w.  s.).    a  treatise  on  the  science  and 

PRACTICE  OF  MIDWIFERY.  Seventh  American  from  the  ninth 
English  edition.  In  one  octavo  volume  of  700  pages,  with  207 
engravings  and  7  plates.     Cloth,  $3.75  net ;  leather,  $4.75,  net. 


the  ablest  English-speaking  authori- 
ties on  the  obstetric  art. — Buffalo 
Medical  and  Surgical  Journal. 


This  work  must  occupy  a  fore- 
most place  in  obstetric  medicine  as 
a  safe  guide  to  both  student  and 
obstetrician.    It  holds  a  place  among 

POCKET  TEXT-BOOKS.   See  page  18. 

POIjITZER  (ADAM).  A  TEXT-BOOK  OF  THE  DISEASES  OF  THE 
KAR  AND  ADJACENT  ORGANS,  New  American  from  the 
fourth  German  edition.  In  one  octavo  volume  of  896  pages,  with 
346  original  engravings.     Cloth,  $7.50,  net.    Just  ready. 


physician  as  a  book  of  reference 
upon  these  topics. — A  m  eric  an 
Journal  of  the  Medical  Sciences. 


It  is  an  absolute  sine  qua  non  for 
the  practitioner  who  devotes  atten- 
tion to  otology  or  rhinology,  and 
should  be  in  the  library  of  every 

POSEY  (W.  C.)  AND  WRIGHT   (JONATHAN),  EDITORS.     A 

TREATISE  ON  THE  EYE,  NOSE,  THROAT  AND  EAR.  By 
Eminent  authorities.  Octavo,  1243  pages,  richly  illustrated  with  650 
engravings  and  35  full-page  plates  in  black  and  colors.  Cloth,  $7.00, 
7ict ;  leather,  $8.00,  net ;  half  Morocco,  $8.50,  net. 
Published  also  in  2  volumes.  Volume  I.  Posey  on  the  Eye.  700  pages, 
358  engravings,  19  plates.  Cloth,  $4.00,  net.  Volume  II,  Wright 
on  the  Nose,  Throat  and  Ear,  543  pages,  292  engravings,  16  plates. 
Cloth,  $3.50,  net. 


The  book  is  a  distinct  success.  It 
will  fulfil  the  aims  of  its  editors  and 
win  popularity  among  students  and 
practitioners. — Johns  Hopkins  Hos- 
pital Bidletin. 

This  is  the  best  book  published  in 
the  English  language  upon  the  eye, 
ear,  nose  and  throat.  In  this  work 
every  chapter  is  excellent.  The 
most  recent  theories  and  methods  of 
treatment  are  incorporated.     It  is  a 


book  which  every  specialist  should 
own,  because  he  will  find  in  it  much 
that  cannot  be  found  in  any  other 
work  of  the  kind,  and  the  book  that 
the  general  practitioner  should  pur- 
chase, for  it  is  especially  adapted  to 
his  needs,  is  strictly  up-to-date,  and 
because  he  can  purchase  no  single 
book  which  will  meet  his  wants  as 
thoroughly  as  will  this  work. — 
Nortfncr.stcrn  Lancet. 


Lka  Brothers  &  Co.,  Philadelphia  and  New   York.     23 


POTTS  (CHARLiES  S.).  A  POCKET  TEXT-BOOK  OF  NERVOUS 
AND  MENTAL  DISEASES.  In  one  handsome  12mo.  volume  of 
445  pages,  with  88  engravings.  Cloth,  $1.75,  net ;  limp  leather,  $2.25, 
net.     See  Lea^s  Series  of  Pocket  Text-hooks^  page  18. 


Far  superior  to  the  ordinary  work 
of  its  class.  The  author  has  suc- 
ceeded in  impressing  the  broad  out- 
lines of  the  structure  and  functions 
of  the  nervous  system  so  simply  and 
so  comprehensively,  with  the  aid 
of  a  few  well-selected  diagrams,  as 
to  make  it  compratively  easy  for  the 


student  to  understand  the  essential 
plan  of  his  future  study.  The  suc- 
ceeding chapters  on  the  various  dis- 
eases, although  condensed,  are  accu- 
rate and  up-to-date,  and  give  in  a 
few  words  the  most  important  facts. 
— Boston  Medical  and  SurgicalJour- 
nal. 


A  TEXT  BOOK  ON  MEDICAL  AND  SURGICAL  ELECTRI- 
CITY.    Octavo,  about  350  pages,  amply  illustrated.     Shortly. 

PROGRESSIVE  MEDICINE.    See  page  32. 

PURDY  (CHARLES  W.).  BRIGHT'S  DISEASE  AND  ALLIED 
AFFECTIONS  OF  THE  KIDNEY.  In  one  octavo  volume  of  288 
pages,  with  18  engravings.     Cloth,  $2. 

PYE-SMITH  (PHIIilP  H.).  DISEASES  OF  THE  SKIN.  In  one 
12mo.  vol.  of  407  pp.,  with  28  illus.,  18  of  which  are  colored.  Cloth,  $2. 

RAL.FE    (CHARIiES  H.).      CLINICAL     CQEMISTRY.     In    one 

12mo.  volume  of  314  pages,  with  16  engravings.    Cloth,  $1.50.    See 
Student's  Series  of  Manuals,  page  27. 

REMSEN  (IRA).  THE  PRINCIPLES  OF  THEORETICAL  CHEM- 
ISTRY.  Fifth  edition,  thoroughly  revised.  In  one  12mo.  vol- 
ume of  326  pages.     Cloth,  $2. 

REYNOLDS  (EDWARD)  AND  NEWELL  (F.  S.).  A  MANUAL 
OF  PRACTICAL  OBSTETRICS.  Second  and  revised  edition. 
Octavo,  531  pages,  illustrated  with  253  engravings,  and  3  plates. 
Cloth,  $3.75,  net. 


A  complete  text-book  on  obstetrics, 
characterized  by  a  distinct  accen- 
tuation of  the  practical  side  of  this 
science. — Interstate  Medical  Journal. 

Seldom  have  we  found  descriptions 


so  complete,  diagnostic  points  so 
clearly  brought  out,  and  the  line  of 
treatment  of  special  conditions  so 
graphically  drawn. — The  Virginia 
Medical  Semi-Monthly. 


RICHARDSON  (BENJAMIN  WARD).      PREVENTIVE  MEDI- 
CINE.    In  one  octavo  volume  of  729  pages.     Cloth,  $4. 


ROBERTS  (JOHN  B.). 

MODERN  SURGERY, 
with  473  engravings  and 


THE  PRINCIPLES  AND  PRACTICE  OF 

Second  and  revised  edition.  Octavo,  838  pages 
^plates.  Cloth,  $4  25,  net;  leather,  $5.25,  net. 


A  clear,  concise,  comprehensive 
and  practical  presentation  of  the 
most  modern  surgery.  The  student 
or  practitioner  will  not  find  a  more 


satisfactory  or  valuable  single  vol- 
ume work  on  this  subject. — Pacific 
Medical  Journal. 


ROBERTS  (SIR  WILLIAM).  A  PRACTICAL  TREATISE  ON 
URINARY  AND  RENAL  DISEASES,  INCLUDING  URINARY 
DEPOSITS.  Fourth  American  from  the  fourth  London  edition.  In 
one  very  handsome  8vo.  vol.  of  609  pp.,  with  81  illus.     Cloth,  $3.50. 


24     Lea  Brothers  &  Co.,  Philadelphia  and  New  York. 

ROCKWELti,  (W.  H.,  Jr.).    A  POCKET  TEXT-BOOK    OF    AN- 
ATOMY.    12mo.,   600    pages,   illustrated.     Cloth,   $2.25,  net;  limp 
leather.  $2.75,  net.       See  lued's  Series  of  Pocket  Text-books,  page  18. 
An  excellent  example  of  skilful  epitomization.     A  compendious  text- 
book for  the  student  and  a  ijuick,  handy  work  of  reference  for  the  physician 
or  surgeon.     Exactly  adapted  to  the  needs  of  training  schools  for  nurses. 

ROGER  (G.  H.).     INFECTIOUS  DISEASES.     Translated   by  M.  S. 
Gabriel,  M.D,    Octavo,  864  pages,  41  illustrations.     Cloth,  $5  75  net. 
Just  ready. 
Symptoms,  pathology,  diagnosis,  I  fore  of  all  things  connected  with  in- 


prognosis  and  treatment  are  con 
sidered  fully  and  practically.  The 
book  is  the  work  of  a  praotieal  man 
who  works  from  a  scientific  basis — 
one  who  knows  the  why  and  where- 


fectious  diseases.  About  two  hun- 
dred pages  are  devoted  to  treatment, 
which  is  presented  in  a  manner  that 
is  at  once  novel  and  yet  eminently 
practical. — The  Medical  Standard. 


ROSS  fJAMES).  A  HANDBOOK  OF  THE  DISEASES  OF  THE 
NERVOUS  SYSTEM.  In  one  handsome  octavo  volume  of  726  pages, 
with  184  engravings.     Cloth,  $4.50 ;  leather,  $5.50. 

SCHAFER    (EDWARD   A.).     THE   ESSENTIALS  OF  HISTOL- 
OGY, DESCRIPTIVE  AND  PRACTICAL.    Sixth  edition.    Octavo, 
426  pages,  with  463  illustrations,     Cloth,  $3.00,  net. 
The  most  satisfactory  elementary    lish  language. — The  Boston  Medical 

text-book  of  histology  in  the  Eng-    and  Surgical  Journal. 

A  COURSE  OF  PRACTICAL    HISTOLOGY.    Second  edition. 

In  one  12mo.  volume  of  307  pages,  with  59  engravings.   Cloth,  $2.25. 

SCHALiEK  (A.).  AN  EPITOME  OF  SKIN  DISEASES.  12mo., 
225  pages,  34  engravings.  Cloth,  $1.00,  net.  See  Lea's  Series  of  Med- 
ical Epitomes,  page  18. 

SCHL.EIF  (WILIilAM).  MATERIA  MEDICA,  THERAPEUTICS, 
PRESCRIPTION  WRITING,  MEDICAL  LATIN,  ETC.  Second 
and  revised  edition.  12mo.,  370  pages.  Cloth,  $1.75;  limp  leather, 
$2.25,  net.    See  Lea's  Series  of  Pocket  Text-hooks,  page  18. 

It  contains  in  a  concise,  definite,  j  plete  college  courses  on  Materia  Med- 
and  assimilable  form  the  essential  i  ica  and  Therapeutics. — The  National 
knowledge  required  in  the  most  com-  |  Medical  Review. 

SCHMAUS  (HANS)  AND  EWING  (JAMES).  PATHOLOGY 
AND  PATHOLOGICAL  ANATOMY.  Sixth  edition.  Octavo,  602 
pages,  with  351  engravings  and  34  plates  in  black  and  colors. 
Cloth,  $4.00,  net. 

This  work  embodies  all   the  re-  |  additions    and    editorial    work    bv 
search  of  the    best  European   and  i  Professor  Ewing  render    the  book 
American  observers,  and  is  without  |  all    the    more    valuable. — Medical 
a  superior,  if  indeed  it  has  an  equal.    Progress. 
in  this  or  any  other  language.     The  i 

SCH3III)T  (I^OUIS  E.).  AN  EPITOME  OF  GENITO-URINARY 
AND  VENEREAL  DISEASES.  12mo.,  24!»  pages,  21  engravings. 
Cloth,  $J, /tc^     See  Lea's  Scries  of  Medical  Lpiionics,  page  18. 


Lea  Bbothicrs  &  Co.,  l*HiLAt)i:LPHiA  and  New  Yoek.     25 


SENN  (NICHOIiAS).  SURGICAL  BACTERIOLOGY.  Second  edi- 
tion. In  one  octavo  volume  of  268  pages,  with  13  plates,  10  of  which 
are  colored,  and  9  engravings.    Cloth,  $2. 

SERIES  OF  CLiINICAIi  MANUALiS.  A  Series  of  Authoritative 
Monographs  on  Important  Clinical  Subjects.  The  following  volumes 
are  now  ready:  Carter  and  Frost's  Ophthalmic  Surgery,  $2.25; 
Marsh  on  Diseases  of  the  Joints,  $2 ;  Owen  on  Surgical  Diseases  of 
Children,  $2;  Pick  on  Fractures  and  Dislocations,  $2. 
For  separate  notices,  see  under  various  authors'  names. 

SERIES  OF  MEDIC Ali  EPITOMES.    See  page  18. 
SERIES  OF  POCKET  TEXT-BOOKS.     See  page  18. 

SERIES  OF  STATE  BOARD   EXAMINATION   QUESTIONS. 

See  page  26. 

SIMON  (CHARLES  E.).  A  TEXT-BOOK  ON  PHYSIOLOGICAL 
CHEMISTRY.  Octavo,  4r>3  pages.    Cloth.  $3.25,  net. 

This  book  is  a  deserving  compan- !  cian.  Simon  has  honored  American 
ion  work  to  Simon^s  Clinical  Diag-  [  medicine  in  his  pioneer  work  in  a 
no.st.s,  and  like  it  will  live  to  l>e-  field  which  heretofore  has  been  oc- 
come  a  standard  and  recognized  cupied  by  foreign  authors.— 7* /le 
text-book  for  students,  and  a  guide  j  Medical  Fortnightly. 
for    the    thoughtful    student-pbysi-  i 


SIMON  (CHARLES  E.).  CLINICAL  DIAGNOSIS,  BY  MICRO- 
SCOPICAL AND  CHEMICAL  METHODS.  New  (5th)  and  revised 
edition.  In  one  octavo  volume  of  695  pages,  with  150  engravings  and 
22  full-page  colored  plates.     Cloth,  $4.00,  net.    Just  ready. 

A  few  notices  of  the  jyrevious  editions  are  appended. 


This  book  thoroughly  deserves  its 
success.  It  is  a  very  complete,  authen- 
tic and  useful  manual  of  the  micro- 
scopical and  chemical  methods 
which  are  employed  in  diagnosis. 
— N.  Y.  Med.  Journal 


The  chapter  on  examination  of 
the  urine  is  the  most  complete  and 
advanced  that  we  know  of  in  the 
English  language. — Canadian  Prac- 
titioner. 


SIMON  (WM.).  MANUAL  OF  CHEMISTRY.  A  Guide  to  Lectures 
and  Laboratory  Work  in  Chemistry.  A  Text-book  specially  adapted 
for  Students  of  Pharmacy  and  Medicine.  Seventh  edition.  In  one 
8vo  volume  of  613  pages,  with  64  engravings  and  8  plates  showing 
colors  of  64  tests,  and  a  spectra  plate.  Cloth,  $3.00,  net. 


It  is  difficult  to  see  how  a  better 
book  could  be  constructed.  No  man 
who  devotes  himself  to  the  practice 
of  medicine  need  know  more  about 
chemistry  than  is  contained  between 
the  covers  of  this  book. —  The  North- 
western Lancet. 

Simon's  Chemistry  has  long  been 
a  favorite  with  teachers  and  with 


students.  It  is  clearly  written  and 
beautifully  and  instructively  illus- 
trated. The  frecjuent  new  editions 
that  are  called  for  allow  the  work  to 
be  kept  up  to  the  latest  researches. 
As  a  text-book  for  medical  students 
it  has  no  superior. — Denver  Medical 
Times. 


SliADE   (D.   D.).     DIPHTHERIA;    ITS    NATURE   AND    TREAT- 
MENT. Second  edition.  In  one  royal  12mo.  vol.,  158  pp.   Cloth,  $1.26. 


26     Lea  Brothers  &  Co.,  Philadelphia  and  New  York, 


SMITH  (J.  LiEWIS).  A  TREATISE  ON  THE  DISEASES  OF  IN- 
FANCY AND  CHILDHOOD.  Eighth  edition,  thoroughly  revised 
and  rewritten  and  much  enlarged.  In  one  large  8vo.  volume  of  983 
pages,  with  273  engravings  and  4  full-page  plates.  Cloth,  $4.50; 
leather,  $5.50. 
For  years  the  leading  text-book  on  |      A  safe  guide  for  students  and  phy- 

children's    diseases  in    America. —    sicians. — The  Am.  Jour,  of  Obstetrics. 

Chicago  Medical  Recorder.  \ 

SMITH  (STEPHEN).  OPERATIVE  SURGERY.  Second  and  thor- 
oughly revised  edition.  In  one  octavo  volume  of  892  pages,  with 
1005  engravings.     Cloth,  $4. 


One  of  the  most  satisfactory  works 
on  modern  operative  surgery  yet 
published.    The  book  is  a  compen- 


dium for  the  modern  surgeon. — Bos- 
ton Medical  and  Surgical  Journal. 


SOLLY  (S.  EDWIN).  A  HANDBOOK  OF  MEDICAL  CLIMA- 
TOLOGY. In  one  handsome  octavo  volume  of  462  pages,  with  en- 
gravings and  11  full-page  plates,  5  of  which  are  in  colors.  Cloth,  $4.00. 
A  clear    and   lucid  summary  of  |  to  its  influence  upon  human  beings. 

what  is  known  of  climate  in  relation  '  — The  Therapeutic  Gazette. 

STARR  (31.  ALLEN).  A  TREATISE  ON  ORGANIC  NERVOUS 
DISE  A  SES.  Octavo,  740  pages,  275  engravings  and  26  colored  plates. 
Cloth,  $6.00,  net;  leather,  $7.00,  net',  half  Morocco,  $7.50,  net. 


The  best  book  on  organic  nervous 
diseases. — Buffalo  Medical  Journal. 

This  book  is  easily  the  best  that 
has  appeared  in  America.  For  the 
student  it  is  especially  to  be  recom- 
mended and  for  the  neurologist  it 
presents  in  a  brief  and  in  a  very 
attractive  way  the  conclusions  of  a 
very  wide  experience. — Interstate 
Medical  Journal. 


It  is  gratifying  to  notice  that 
special  care  has  been  exercised 
throughout  the  book  to  give  prom- 
inence to  the  question  of  treatment. 
It  deserves  to  take  its  place  among 
the  best  text-books  in  English  upon 
diseases  of  the  nervous  system. — 
Johns  Hopkins  Hospital  Bulletin. 

Especially  in  regard  to  treatment 
the  statements  are  full  and  precise. 
— Cleveland  Medical  Journal. 

STATE  BOARD  EXAMINATION  SERIES.  CLASSIFIED  AND 
EDITED  BY  R.  J.  E.  SCOTT,  A.M.,  M.D.  Containing,  with 
answers  or  references,  every  question  asked  at  all  of  the  examinations 
held  by  the  New  York  State  Board  of  Medical  Examiners.  The  best 
guides  to  similar  examinations  in  other  States.  In  7  volumes,  bound  in 
flexible  cloth,  each  containing  from  200  to  300  12mo.  pages,  printed 
on  paper  suitable  for  either  pen  or  pencil,  every  other  page,  opposite 
text,  being  left  blank  for  memoranda.  Price,  $1.50  per  volume. 
The  respective  volumes  cover  the  subjects  of  Anatomy,  (ready), 
Chemistry,  (ready),  Obstetrics,  (ready),  Surgery,  (ready),  Practice, 
Materia  Medica  and  Therapeutics,  (ready).  Pathology  and  Diagnosis, 
(ready),  Physiology  and  Hygiene,  (preparing). 

STENHOUSE  (JOHN).    AN  EPITOME    OF    PATHOLOGY.      See 

Lea's  Series  of  Medical  Epitomes,  page  18. 

STILLE  (ALFRED).  CHOLERA;  ITS  ORIGIN,  HISTORY,  CAUS- 
ATION, SYMPTOMS,  LESIONS,  PREVENTION  AND  TREAT- 
MENT. In  one  12mo.  volume  of  163  pages,  with  a  chart  showing 
routes  of  previous  epidemics.     Cloth,  $1.25. 

THERAPEUTICS   AND    MATERIA    MEDICA.      Fourth    and 

revised  edition.      In  two  octavo  volumes,  containing    1936    pages. 
Cloth,  $10;  leather,  $12. 


Lea  Brothers  &  Co.,  Philadelphia  and  New  York.     27 

STILiliE  (AliFRED),  MAISCH  (JOHN  M.)  AND  CASPARl 
(CHAS.  JR.).  THE  NATIONAL  DISPENSATORY:  Containing 
the  Natural  History,  Chemistry,  Pharmacy,  Actions  and  Uses  of 
Medicines,  including  those  recognized  in  the  latest  Pharmacopoeias  of 
the  United  States,  Great  Britain  and  Germany,  with  numerous  refer- 
ences to  the  French  Codex.  Fifth  edition,  revised  and  enlarged, 
including  the  U.  S.  Pharmacopoeia,  Seventh  Decennial  Revision. 
With  Supplement  containing  the  National  Formulary.  In  one 
magnificent  imperial  octavo  volume  of  about  2025  pages,  with 
320  engravings.  Cloth,  $7.25;  leather,  $8.  With  ready  reference 
Thumb-letter  Index.     Cloth,  $7.75  ;  leather,  $8.50. 

STIMSON  (IjEWIS  A.).  A  MANUAL  OF  OPERATIVE  SURGERY. 
Fourth  edition.  In  one  royal  12mo.  volume  of  581  pages,  with  293 
engravings.     Cloth,  $3.00,  net. 


The  book  is  worth  the  price  for  the 
illustrations  alone. — Ohio  3fedical 
Journal. 

Well  written,  clear,  concise,  prac- 
tical, and  thoroughly  up-to-date  in 


every  particular.  It  covers  the  field 
so  thoroughly  as  to  make  it  a  very 
valuable  text-book  and  a  ready 
reference-book  for  surgeons. — Kan- 
sas City  Medical  Record. 


STIMSON  (LEWIS  A.).      A  TREATISE  ON  FRACTURES    AND 
DISLOCATIONS.      Third  edition.      In  one  handsome  octavo  vol- 
ume of  842  pages,  with  336  engravings  and  32  plates.     Cloth,  $5.00, 
net;  leather,  $6.00,  we«;  half  Morocco,  $6.50,  wg<. 
Preeminently   the    authoritative  |  value.     The  woi-k  is  profusely   il- 
text-book  upon  the   subject.      The    lustrated.     It  will  be   found  indis- 
vast  experience  of  the  author  gives  1  pensable  to  the  student  and  the  prac- 
to  his  conclusions  an  unimpeachable  \  titioner  alike. — The  Medical  Age. 

STUDEJNT'S  QUIZ  SERIES.  Thirteen  volumes,  convenient,  author- 
itative, well  illustrated,  handsomely  bound  in  cloth.  1.  Anatomy 
(double  number);  2.  Physiology;  3.  Chemistry  and  Physics;  4.  Histol- 
ogy, Pathology,  and  Bacteriology;  5.  Materia  Medica  and  Thera- 
peutics ;  6.  Practice  of  Medicine ;  7.  Surgery  (double  number);  8.  Genito- 
urinary and  Venereal  Diseases ;  9.  Diseases  of  the  Skin;  10.  Diseases 
of  the  Eye,  Ear,  Throat  and  Nose;  11.  Obstetrics;  12.  Gynecology ; 
13.  Diseases  of  Children.  Price,  $1  each,  except  Nos.  1  and  7, 
Anatomy  and  Surgery,  which  being  double  numbers  are  priced  at 
$1.75  each.     Full  specimen  circular  on  application  to  publishers. 

STUDENT'S  SERIES  OP  MANUALS.  12mos.  of  from  300-540 
pages,  profusely  illustrated,  and  bound  in  red  limp  cloth.  Bruce's 
Materia  Medica  and  Therapeutics  (sixth  edition),  $1.50.  net.  Klein's 
Elements  of  Histology  (5th  edition),  $2.00,  net ;  Pepper's  Surgical 
Pathology,  $2;  Treves'  Surgical  Applied  Anatomy,  $2.00,  net. 
Ralfe's  Clinical  Chemistry,  $1.50.  Herman's  First  Lines  in  Mid- 
wifery, $1.25. 
For  separate  notices,  see  under  various  author's  namea. 

STURGES  (OCTAVIUS).  AN  INTRODUCTION  TO  THE  STUDY 
OF  CLINICAL  MEDICINE.     In  one  12mo.  volume.     Cloth,  $1.25. 

SUTER  (W.  NORWOOD).    A  MANUAL  OF  REFRACTION  AND 
MOTILITY.       12mo.,  382  pages,  101  engravings,  4  colored  plates. 
Cloth,  $2,  7iet. 
A  text-book  which  can  be  readily  I  The  work  is  devoid  of  bias,  is  direft 
understood    by    the     beginner     in  j  and  accurate,  and  is  undoubtedly  the 
ophthalmology  and  sufficiently  com- j  best    that    has    been    published   in 
plete  to  meet  the   requirements   of !  recent  years. — Medical  Record. 
advanced  students  and  practitioners.  I 


28     Lea  BEOTHfifts  &  Co.,  PHiLADfiLi»HiA  and  New  York. 


SUTTON  (JOHN  BLAND).  SURGICAL  DISEASES  OF  THE 
OVARIES  AND  FALLOPIAN  TUBES.  Including  Abdominal 
Pregnancy.  In  one  12mo.  volume  of  513  pages,  with  119  engravings 
and  5  colored  plates.     Cloth,  $3. 

SZYMONOWICZ    (li.)   AND    MacCALLiUM   (J.   BRUCE).       A 

TEXT- BOOK  OF  HISTOLOGY  OF  THE  PIUMAN  BODY  :  in- 
cluding Microscopical  Technique.  Octavo,  437  pages,  with  277 
original  engravings  and  57  inset  plates  in  black  and  colors,  contain- 
ing 81  figures.     Cloth,  $4.75,  net. 


This  book  will  take  its  place 
among  the  lirst  favorites  of  the  text- 
books on  biology. — Journal  A  nieri- 
can  Medical  Association. 

Eminently  satisfactory   and  well 


adapted  for  teaching  purposes;  the 
text  is  accurate  and  modern,  the 
illustrations  are  extremely  beautiful, 
well  selected  and  numerous. — Medi- 
cal Record. 


TAIT  (L.AWSON).     DISEASES  OF  WOMEN  AND  ABDOMINAL 
SURGERY.    Octavo,  546  pages  and  3  plates.    Cloth,  $3. 

TAYLOR  (ALFRED  S.).     MEDICAL   JURISPRUDENCE.     New 

American  from  the  twelfth  English  edition,  specially  revised  by  Clark 

Bell,  Esq.,  of  the  N.  Y.  Bar.     In  one  8vo.  vol.  of  831  pages,  with  54 

engravings  and  8  full-page  plates.     Cloth,  $4.50;  leather,  $5.50. 

To  the  student,  asto  the  physician,    be  found  to  be  thorough,  authorita- 

we  would  say,  get   Taylor  first,  and    tive     and     modern. — Albany     Law 

then  add  as  means  and  inclination    Journal. 

^nohlQ  YOM.—AmeHcan  Practitioner  \      probably  the  best  work  on  the 
and  News.  !  subject  written  in  the  English  Ian- 

It  is  the  authority  accepted  as  guage.  The  work  has  been  thor- 
final  by  the  courts  of  all  English-  oughly  revised  and  is  up  to  date. — 
speaking  countries.    The  work  will '  Pacific  Medical  Journal. 

TAYLOR  (ROBERT  W.).  GENITO-URINARY  AND  VENEREAL 

DISEASES    AND    SYPHILIS.     New  (3d)  and  revised  edition.     In 
one  very  handsome  octavo  volume  of  about  750  pages,  with  153  en- 
gravings and  39  colored  plates.        Cloth,  $5.00,  net;  leather,  $f).00, 
net;  half  morocco,  $6.50,  nef.    Just  ready. 
A  few  notices  of  the  previous  edition  are  appended. 
By  long  odds  the  best  work  on  \      It  is  a  veritable  storehouse  of  our 

venereal  diseases. — Louisville  Medi-  \  knowledge  of  the  venereal  diseases. 

cal  Monthly.  j  It  is  commended  as   a  conservative, 

The  clearest,   most  unbiased  and  I  practical,    full    exposition     of  the 

ably  presented  treatise  as  yet  pub- I  greatest    value.— C/Mca^o    Clinical 

lished    on    this   vast   subject. — The    -t^ewct^. 

Medical  News.  ' 

TAYLOR  (ROBERT  W.).     A  PRACTICAL  TREATISE  ON  SEX- 
UAL   DISORDERS  IN   THE    MALE  AND   FEMALE.      Second 
edition.     In  one  8vo.  volume  of  434  pages,  with  91  engravings  and 
13  colored  plates.     Cloth,  $3.00,  net. 
The  author  has  presented  to   the    followed,  will  be  of  unlimited  value 

profession  the  ablest  and  most  scien-    to    both    physician    and   patient. — 

tific  work  as  yet  published  on  sexual    Medical  News. 

disorders,  and  one  which,  if  carefully 

A  CLINICAL  ATLAS  OF  VENEREAL  AND  SKIN  DISEASES. 

Including  Diagnosis,  Prognosis  and  Treatment.  In  eight  large  folio 
parts,  measuring  14  x  18  inches,  and  comprising  213  beautiful  figures 
on  58  full-page  chromo-lithographic  plates,  85  fine  engravings  and  425 
pages  of  text.  Bound  in  one  volume,  half  Turkey  Morocco,  $28. 
For  tale  by  subscription  only.     Address  the  publishers. 


Lea  Brothebs  &  Co.,  Philadelphia  and  New  York.    29 

TAYIiOR  (SEYMOUR).  INDEX  OF  MEDICINE.  A  Manual  for 
the  use  of  Senior  Students  and  others.  In  one  large  12mo.  volume  of 
802  pages.    Cloth,  $3.76. 

THOMAS  (T.  GAILiIjARD)  AND  MUNDE  (PAUL  P.).  A  PRAC- 
TICAL TREATISE  ON  THE  DISEASES  OF  WOMEN.  Sixth 
edition.  In  one  octavo  volume  of  824  pages,  with  347  engravings. 
Cloth,  $5 ;  leather,  $6. 

THOMPSON  (W.  OILMAN).  A  TEXT-BOOK  OF  PRACTICAL 
MEDICINE.  For  Students  and  Practitioners.  Second  edition,  thor- 
oughly revised.  In  one  handsome  octavo  volume  of  1014  pages, 
with  59  engravings.  Cloth,  $5.00,  net;  leather,  $6.00,  net;  half 
Morocco,  $6.50,  net. 


The  author  has  presented  the  rich 
harvest  of  his  ripe  experience  as 
physician   and    teacher.      There  i 


direct  and  most  satisfying  manner 
he  has  given  in  sufficient  detail  the 
exact  method  of  treatment  that  has 


every  where  ample  evidence  of  accur-  commended  itself  to  his  judgment 
ate  observation,  profound  scholar- 1  and  his  experience. — Medical  News. 
ship  and  rare  good  judgment.     In  a  I 

THOMPSON  (SIR  HENRY).  THE  PATHOLOGY  AND  TREAT- 
MENT OF  STRICTURE  OF  THE  URETHRA  AND  URINARY 
FISTULA.  From  the  third  English  edition.  In  one  octavo  volume 
of  359  pages,  with  47  engravings  and  3  lithographic  plates.  Cloth, 
$3.50. 

THORNTON  (E.  Q.).  FORMULARY.  See  Medical  News  Pocket 
Fornndar!/,  V^S^  32. 

TIRARD   (NESTOR).     MEDICAL   TREATMENT  OF  DISEASES 
AND  SYMPTOMS.     Handsome  octavo  volume  of  627  pages.     Cloth, 
$4.00,  net. 
This  work  will  rapidly  come  into  I  this  is  a  work  destined  to  become 
favor  with  students  and  practition- 1  popular,  and  we  take  great  pleasure 
ers.     It  deals  comprehensively  with    in   commending  it  in   the    highest 
therapeutical  medications  and  pre-    terms. — Nashville  Journal  of  3fedi- 
sents  a  great  number  of  well-selected  |  ciyie  and  Surgery. 
formulas  of  every  day  use.  Certainly  1 

TREVES  (SIR  FREDERICK).    OPERATIVE  SURGERY.    New 

edition,  revised  by  the  author  and  Jonathan  Hutchinson,  ,Ik., 
F.R.C.S.  In  two  8vo.  volumes,  containing  1574  pages,  with  474  illus- 
trations. De  luxe  edition,  half  Morocco,  $6.50,  net,  per  volume. 
Ju)it  read)/. 

A  SYSTEM  OF  SURGERY.    In  Contributions  by  Twenty -five 

English  Surgeons.  In  two  large  octavo  volumes,  containing  2298 
pages,  with  950  engravings  and  4  plates.     Per  set,  cloth,  $16.00. 

SURGICAL    APPLIED    ANATOMY.      New   edition.      In   one 


12mo.  volume  of  577  pages,  with  80  engravings.     Cloth,  $2.00,  net. 
See  Student's  Series  of  Manuals,  page  27. 

TULEY  (HENRY  E.).  AN  EPITOME  OF  PEDIATRICS.  ]2mo., 
266  pages,  33  engravings.  Cloth,  $1,  net.  See  Lea's  Series  of  Medical 
Epitotncs,  page  18. 

TUTTLE  (GEORGE  M.).  A  POCKET  TEXT-BOOK  OF  DISEASES 
OF  CHILDREN.  In  one  handsome  12mo.  volume  of  374  pages, 
with  5  plates.  Cloth,  $1.50,  net ;  flexible  red  leather,  $2.00,  7iet.  See 
Lea's  Series  of  Pocket  Text-hooks,  page  18. 


It  is  a  good  work — the  author  hav 
ing  condensed  most  of  the  leading 
points  in  connection  with   diseases 


of  infancy  and  childhood  into  short 
and  readable  chapters. —  Virginia 
Medical  Semi- 3Ionlhly . 


30     Lka  Brothebs  a  Co.,  Philadelphia  and  New  York. 


VAUGHAN    (VICTOR    C.)    AND    NOVY    (FREDERICK    G.). 

CELLULAR  TOXINS,  or  the  Chemical  Factors  in  the  Causation  of 
Disease.  New  (4th)  edition.  In  one  12mo.  volume  of  480  pages.  Cloth, 

$3.00,  }ict. 

The  work  has  been  brought  down  i  The  most  exhaustive  and  most  re" 
to  date,  and  will  be  found  entirely  cent  presentation  of  the  subject. — 
satisfactory. — Joxtmal  of  theAmeri-  '  American  Jour,  of  the  Med.  Sciences, 
can  Medical  Association.  i 


VEASEY  (CliARENCE  A.)  A  MANUAL  OF  OPHTHALMOLOGY 

12mo.,  410  pages,  194  engravings,  10  colored  plates.     Cloth,  $2. 00,  net 

The  best  eye  manual  we  have 
seen.  A  handy  volume,  clearly, 
concisely,  conservatively  written 
and  well  arranged.  The  treatment 
is   well  up-to-date  — / ournal     of 


Ophthalmology,   Otology  and  Laryn- 
gology. 
A  very  attractive,  practical  and 


intereKsting  volume.  A  book  that 
should  be  constantly  in  the  hands 
of  the  studentof  ophthalmology,  and 
one  well  suited  for  the  busy  oculist 
who,  in  the  midst  of  his  work,  may 
not  have  time  to  look  up  more  ex- 
tensive volumes,  St.  Paul  Medical 
Journal. 


VISITING     lilST.       THE    MEDICAL    NEWS    VISITING    LIST. 

Four  styles:  Weekly  (dated  for  30  patients);  Monthly  (undated  for 
120  patients  per  month);  Perpetual  (undated  for  30  patients  each 
week);  and  Perpetual  (undated  for  60  patients  each  week).  The  60- 
patient  book  consists  of  256  pages  of  assorted  blanks.  The  first  three 
styles  contain  32  pages  of  important  data,  thoroughly  revised,  and 
160  pages  of  assorted  blanks.  Each  in  one  volume,  price,  $1.25. 
With  thumb-letter  index  for  quick  use,  25  cents  extra.  Special  rates 
to  subscribers  to  The  Medical  News  or  The  American 
Journal  of  the  Medical  Sciences,  or  both.  See  p.  32. 


von  BERGMANN  (E.),  von  BRUNS  (P.)  and  von  MIKULICZ  (J.) 

A  SYSTEM  OF  PRACTICAL  SURGERY.  Translated  and  edited 
under  the  supervision  of  William  T.  Bull,  M.D.  In  five  imperial 
octavo  volumes  containing  over  4000  pages,  with  about  1600  engrav- 
ings and  110  full-page  colored  plates.  Per  volume,  cloth,  $6,  ne/ ; 
leather,  $7,  net ;  library  binding,  $7,  net ;  half  Morocco,  $8.50,  net.  For 
sale  by  subscription  only.     Full  prospectus  on  application. 


The  work  is  an  exhaustive  one, 
and  in  its  entirety  will  form  a  com- 
plete encyclopedia  of  modern  surgi- 
cal knowledge.  Abundant  data,  the 
result  of  careful,  original  research  in 
special  fields,  are  published,  with  ex- 
act clinical  reports  that  are  of  im- 
mense practical  value.     As  a  whole, 


the  series  forms  the  most  important 
surgical  work  of  the  day,  and  it  will 
be  found  of  incalculable  value  to  the 
student  and  to  the  scientific  surgeon, 
as  reflecting  the  most  advanced  and 
approved  methods  of  modern  surgi- 
cal practice. — Detroit  Medical 
Journal. 


WATHEN  (JOHN  R.).    AN  EPITOME  OF  HISTOLOGY.     12mo., 

229  pages  with  114  engravings;     Cloth,  $1,  net.      See  Lea's  Scries  of 
Medical  Epitomes,  page  18. 


WATSON  (THOMAS).  LECTURES  ON  THE  PRINCIPLES  AND 
PRACTICE  OF  PHYSIC.  A  new  American  from  the  fifth  and 
enlarged  English  edition,  with  additions  by  H.  Hartshorne,  M.D. 
In  two  large  8vo.  vols,  of  1840  pp.,  with  190  cuts.  Cloth,  $9 ;  leather,  $11. 


Lea  Brothers  &  Co.,  Philadelphia  and  New  York.     31 


WHARTON  (HENRY  R.).  MINOR  SURGERY  AND  BANDAG- 
ING. Fifth  edition.  In  one  12mo.  volume  of  640  pages,  with 
509  engravings,  many  of  which  are  photographic.     Cloth,  $3.00,  net. 


The  part  devoted  to  bandaging  is 
perhaps  the  best  exposition  of  the 
subject  in  the  English  language.  It 
3an  be  highly  commended  to  the 
student,  the  practitioner  and  the 
specialist. — The  Chicago  Medical 
Recorder. 


Well  written,  conveniently  ar- 
ranged and  amply  illustrated.  It 
covers  the  field  so  fully  as  to  render 
it  a  valuable  text-book,  as  well  as  a 
work  of  ready  reference  for  sur- 
geons.— North    Amer.  Practitioner. 


WHITL.A  (TVTLLiIAM).  DICTIONARY  OF  TREATMENT,  OR 
THERAPEUTIC  INDEX.  Including  Medical  and  Surgical  Thera- 
peutics.    In  one  square  octavo  volume  of  917  pages.     Cloth,  $4. 

WHITMAN  (ROYAL.).  ORTHOPEDIC  SURGERY.  New  (2d) 
edition,  thoroughly  revised.  Octavo,  843  pages,  with  507  engravings, 
mostly  original.     Cloth,  $5.50,  net. 


The  standard  authority  on  ortho- 
pedic surgery.  —  Virginia  Medical 
Monthly. 

It  is  a  pleasure  to  review  a  book 
so  well  written  and  so  clearly  illus- 
trated as  this,  presenting  the  last 
and  best  word  on  this  active  special 


branch.  The  text  is  clear  and  the 
views  expressed  are  well  presented, 
making  the  work  the  ))est  that  has 
yet  been  offered  in  this  important 
branch. — The  Boston  Medical  and 
Surgical  Journal. 


WICKS  (MAUD  A.).    A  POCKET  TEXT-BOOK  OF  NURSING. 

Preparing.     See   Lea's  Series   of  Pocket   Text-books,  page  18. 

WILLIAMS  (DAWSON).    THE  MEDICAL  DISEASES  OF  CHIL- 
DREN.     Second  edition.      Specially  revised  for  America  by  F.  S. 
Churchill,  A.M.,  M.D.     In  one  octavo  volume  of  538  pages,  with 
52  illustrations,  and  2  plates.     Cloth,  $3.50,  net. 
The  descriptions  of  symptoms  are  1  diagnosis,  prognosis,  complications, 

full,  and  the  treatment  recommended  !  and  treatment.    The  work  is  up  to 

will  meet  general  approval.    Under  I  date  in  every  sense. — The  Charlotte 

each  disease  are  given  the  symptoms,  I  Medical  Journal. 

WILSON  (ERASMUS).  A  SYSTEM  OF  HUMAN  ANATOMY. 
A  new  and  revised  American  from  the  last  English  edition.  Illustrated 
with  397  engravings.  In  one  octavo  volume  of  616  pages.  Cloth,  $4 ; 
leather,  $5. 

WOOLSEY  (GKORGE).  APPLIED  SURGICAL  ANATOMY  RE- 
(tIONALLY  presented.  Octavo,  511  pages,  with  125  original 
illustrations  in  black  and  colors.   Cloth, $5.00,  net',  leather, $6.00, nc^ 


A  happy  union  of  fact  and  prac- 
tice, the  latter  based  upon  the  for- 
mer, which  brings  into  distinct  view 
th«»  enhanced  advantage  that  can  be 
taken  of  this  combination.  The 
book  bristles  with  good  advice.  It 
is  a  book  of  remarkable  merit,  show- 


ing not  merely  a  large  amount  of 
research,  but  also  the  faculty  of 
giving  to  each  anatomical  fact  its 
value  when  applied  in  practice. 
The  work  is  sufficiently  illustrated. 
— American  Journal  of  the  Medical 
Sciences. 


ZAPFFE  (F.  C).  A  POCKET  TEXT-BOOK  OF  BACTERIOLOGY. 
Handsome  12mo.  of  360  pages,  amply  illustrated  with  146  engravings 
and  7  colored  plates.  Cloth,  $\.bO,net',  limp  leather,  $2.00,  ?ief, 
See  Lea\s  Series  of  Pocket  Text-books,  page  18. 


A  most  thorough  and  practical 
book,  written  for  the  needs  of  both 
students  and  practitioners. — Louis- 


ville Journal  uf  Medicine  and  Siir- 
gery. 


PERIODICALS 


PROGRESSIVE  MEDICINE. 

A  Quarterly  Digest  of  New  Methods,  Discoveries,  and  Improvements 
in  the  Medical  and  Surgical  Sciences  by  Eminent  Authorities.  Edited  by 
Dr.  Hobart  Amory  Hare.  In  four  illustrated  octavo  volumes  of  300- 
400  pages  each,  issued  quarterly,  commencing  March  of  each  year. 
Per  annum  (4  volumes),  in  heavy  paper  covers,  $6,  net ;  in  cloth  binding, 
$9,  net,  delivered. 

THE  MEDICAL  NEWS. 
Weekly,  S4.00  per  Annum. 

Each  number  contains  48  quarto  pages,  abundantly  illustrated.  A 
crisp,  fresh  weekly  professional  newspaper. 


THE  AMERICAN  JOURNAL,  OF  THE  MEDICAL  SCIENCES. 

Monthly,  $5.00  Ptr  Annum. 

Each  issue  contains  192  octavo  pages,  fully  illustrated.    The  most 
advanced  and  enterprising  American  exponent  of  scientific  medicine. 


THE   MEDICAL  NEWS  VISITING   LIST. 

Four  styles,  Weekly  (dated  for  30  patients) ;  Monthly  (undated,  for 
120  patients  per  month) ;  Perpetual  (undated,  for  30  patients  weekly  per 
year);  and  Perpetual  (undated,  for  60  patients  weekly  per  year).  Each 
style  in  one  wallet-shaped  book,  leather  bound,  with  pocket,  pencil  and 
rubber.     Price,  each,  $1.25.     Thumb-letter  index,  25  cents  extra. 


THE  MEDICAL  NEWS  POCKET  FORMULARY. 

Fifth  Edition 

Containing  over  1700  prescriptions  representing  the  latest  and  most  ap- 

f)roved   methods  of  administering  remedial   agents.     Strongly  bound  in 
eather  ;  with  pocket  and  pencil.     Price,  $1.50,  net. 


COMBINATION    RATES: 

Progressive  Medicine per  annum,  $  6  00 

The  American  Journal  of  the  Medical  Sciences        ...       "  5  00 

The  nedical  News "  4  00 

Progressive  Medicine  and  The  American  Journal    ...       "  10  00 

Progressive  Medicine  and  The  Medical  News "'  9  00 

The  American  Journal  and  The  Medical  News "  8  00 

Prog.  Medicine,  The  Amer.  Jour,  and  The  Med^^  News  "  13  SO 
The  Medical  News  Visiting  List   in   combindtioM  with    any   of   the 

above  Periodicals •   •   •  • 75 

The  Medical   News  Pocket   Formulary  irt   combination    with    any 

of  the  above  Henodicals .V 75 

Full  Circulars  au<^^Speeimens  fr«e. 

LEA  BROTHERS  &Ca.,  Publishers, 

706,  708  &  710  Sansom  «t.,  PhiladelpWa. 
Ill  EUth  Avenue,  New  York, 


UNIVERSITY  OF  CALIFORNIA 

MEDICAL   CENTER   LIBRARY 

THIS  BOOK  IS  DUE  ON  THE  LAST  DATE 
STAMPED  BELOW 

Books  not  returned  on  time  are  subject  to  a  fine  of  50c 
per  volume  after  the  third  day  overdue,  increasing  to 
$1.00  per  volume  after  the  sixth  day.  Books  not  in  de- 
mand may  be  renewed  if  application  is  made  before  expi- 
ration of  loan  period. 


3m-l,*41(767s) 


QR46 
1903 


•-S4<^t0riology^ 


52400 


